Metal alloy for hydraulic applications

Abstract

The wear-resistant hydraulic system includes a first copper-based alloy having the formula (I) Cu a Sn b Zn c M d , where M is a combination of up to six transition metals, metalloids, and / or alkali metals, a is any number between 0.50 and 0.93, b is any number between 0.00 and 0.07, c is any number between 0.00 and 0.40, and d is any number between 0.01 and 0.40, and a second copper-based alloy that includes at least 50 wt% Cu based on the total weight of the alloy; and at least one compound of formula (II) A x B y , where A is Cu, Sn, or Zn, B is Co, Cr, In, Mn, Mo, Ni, Rb, Sb, Te, or Ti, x is any number between 1 and 53, and y is any number between 1 and 16, and the first or second alloy has a bulk modulus K VRH value of approximately 70 to 304 GPa.

Description

Technical Field

[0001] The present disclosure relates to metal alloys configured for hydraulic applications having reduced or no lead content, and methods of identifying and producing the same. Background of the Invention

[0002] The discovery of metal alloys such as bronze and brass has enabled technological progress for humanity because alloy materials are harder and more durable than pure metals. Over time, various combinations of metals have been identified and used to further improve the desirable properties of bronze and brass. However, many of these improvements include toxic materials such as arsenic or lead, which are problematic for both humans and the environment. Summary of the Invention

[0003] In one or more embodiments, a wear-resistant hydraulic system is disclosed. The system includes a first copper-based alloy having formula (I):

[0004] Cu a Sn b Zn c M d (I),

[0005] where

[0006] M is a combination of up to six transition metals, metalloids, and / or alkali metals,

[0007] a is any number between 0.50 and 0.93,

[0008] b is any number between 0.00 and 0.07,

[0009] c is any number between 0.00 and 0.40, and

[0010] d is any number between 0.01 and 0.40.

[0011] The system may further include a second copper-based alloy that contains at least 50 wt% Cu, based on the total weight of the alloy, and at least one compound of formula (II):

[0012] A x B y (II),

[0013] where

[0014] A is Cu, Sn, or Zn,

[0015] B is Co, Cr, In, Mn, Mo, Ni, Rb, Sb, Te, or Ti,

[0016] x is any number between 1 and 53, and

[0017] y is any number between 1 and 16.

[0018] The first or second alloy may have a bulk modulus K of about 70 to 304 GPa VRH value. M may be Sb, Te, Co, Rb, Mo, In, W, Tl, Al, Fe, Mn, Ni, Pb, Si, or a combination thereof. The first and / or second copper-based alloy may be doped with Ni, Co, W, or a combination thereof. The doping may be up to about 2 wt% based on the total weight of the alloy. c may be 0.02. B may be Co, In, or Ni. The first alloy may have the formula Cu 0.93 Sn 0.06 W 0.01 . The at least one compound of formula (II) may be SnNi3. The hydraulic system may include an axial piston pump.

[0019] In another embodiment, a copper-based alloy is disclosed. The alloy comprises at least 50 wt% Cu, and at least one compound of formula (II):

[0020] A x B y (II),

[0021] wherein

[0022] A is Cu, Sn, or Zn,

[0023] B is Co, Cr, In, Mn, Mo, Ni, Rb, Sb, Te, or Ti,

[0024] x is any number between 1 and 53, and

[0025] y is any number between 1 and 16.

[0026] B may be Co, In, or Ni. The at least one compound of formula (II) may be SnNi3. The at least one compound of formula (II) may include two different compounds. The two different compounds may have B = Ni. The alloy may have a bulk modulus K of about 70 to 304 GPa VRH value. The at least one compound of formula (II) may include a mixture of compounds, wherein at least one has A = Sn, and wherein at least one has A = Zn.

[0027] In an alternative embodiment, a copper-based alloy is disclosed. The alloy has the formula (I):

[0028] Cu a Sn b Zn c M d (I),

[0029] wherein

[0030] M is at least one of Sb, Te, Co, Rb, Mo, In, W, or Tl, Al, Fe, Mn, Ni, Pb or Si,

[0031] a is any number between 0.50 and 0.93,

[0032] b is any number between 0.00 and 0.07,

[0033] c is any number between 0.00 and 0.40, and

[0034] d is any number between 0.01 and 0.40.

[0035] The copper-based alloy may be doped with Ni, Co, W, or a combination thereof. d may be 0.02, c may be 0.00, and M may be Mo, In, Sb, or Te. The alloy may have a bulk modulus K in the range of about 70 to 304 GPa VRH value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of a non-limiting example of a hydraulic system of an axial piston pump;

[0037] Figure 2A is a 4D plot of the Cu-Pb-Sn-O chemical space, related to Example 1 in contact with air (O);

[0038] Figure 2B is a 4D plot of the Cu-Zn-Al-Ni-Si-Fe-O chemical space, related to Example 2 in contact with air (O);

[0039] Figure 2C is a 4D plot of the Cu-Sn-Bi-O chemical space, related to Example 3 in contact with air (O);

[0040] Figure 3 is a phase diagram between O2 gas and Example 1;

[0041] Figure 4A shows a photograph of a distributor plate made of the alloy of Example 3, with cracks present in region B; and

[0042] Figure 4B shows Figure 4A a backscattered electron imaging (BEI) image of region B shown in , where the bright spots correspond to Bi-rich precipitates. DETAILED DESCRIPTION OF THE INVENTION

[0043] Embodiments of the present disclosure are described herein. However, it is to be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Accordingly, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching one skilled in the art to employ the embodiments of the present application in various ways. As will be understood by one of ordinary skill in the art, the various features shown and described with reference to any one of the drawings may be combined with features shown in one or more other drawings to produce embodiments that are not explicitly shown or described. Combinations of the shown features provide representative embodiments for typical applications. However, various combinations and modifications of the features may be required for a particular application or implementation consistent with the teachings of the present disclosure.

[0044] Except as in the examples or otherwise explicitly stated, all numerical quantities in this specification indicating amounts of materials or reaction conditions and / or use conditions should be understood to be modified by the word "about" to describe the broadest scope of the present disclosure. Practice within the stated numerical ranges is generally preferred. Further, unless otherwise stated to the contrary: percentages, "parts" and ratio values are by weight; describing a group or class of materials as suitable or preferred for a given purpose in connection with the present disclosure means that a mixture of any two or more members of the group or class is likewise suitable or preferred; the chemical term description of a component refers to the component as added to any combination specified in the specification, and does not necessarily preclude chemical interactions among the components of the mixture once mixed.

[0045] The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation in this document, with necessary modifications to normal grammatical variants of the initially defined abbreviation. Unless otherwise stated to the contrary, measurements of properties are made by the same technique as that previously or subsequently involved for the same property.

[0046] It must also be noted that, unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used in the specification and the appended claims include plural referents. For example, reference to a component in the singular includes a plurality of components.

[0047] As used herein, the terms "substantially", "generally", or "about" mean that the relevant quantity or value can be a specified particular value or some other value near it. Generally, the term "about" indicating a particular value is intended to mean a range within ±5% of that value. As an example, the phrase "about 100" represents a range of 100 ± 5, i.e., a range from 95 to 105. Generally, when the term "about" is used, it can be expected that similar results or effects according to the present disclosure can be obtained within the range of ±5% of the indicated value. The term "substantially" can modify the values or relative characteristics disclosed or claimed in the present disclosure. In such cases, "substantially" can mean that the value or relative characteristic it modifies is within ±0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, or 10% of that value or relative characteristic.

[0048] It should also be understood that integer ranges explicitly include all intermediate integers. For example, the integer range 1 - 10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4,... 97, 98, 99, 100. Similarly, when any range is required, the intermediate numbers as the increment of the difference between the upper and lower limits divided by 10 can be taken as alternative upper or lower limits. For example, if the range is 1.1 to 2.1, the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as the lower or upper limit.

[0049] In the examples shown herein, the concentration, temperature, and reaction conditions (such as pressure, pH, flow rate, etc.) can be implemented with values rounded or truncated to ±50% of the value with two significant figures provided in the examples. In one refinement, the concentration, temperature, and reaction conditions (such as pressure, pH, flow rate, etc.) can be implemented with values rounded or truncated to ±30% of the value with two significant figures provided in the examples. In another refinement, the concentration, temperature, and reaction conditions (such as pressure, pH, flow rate, etc.) can be implemented with values rounded or truncated to ±10% of the value with two significant figures provided in the examples.

[0050] For all compounds represented by empirical chemical formulas with multiple letter and number subscripts (such as CH2O), the subscript values can be rounded or truncated to ±50% of the indicated value with two significant figures. For example, if represented as CH2O, it is the compound of formula C (0.8-1.2) H (1.6-2.4) O (0.8-1.2) In one refinement, the subscript values can be rounded or truncated to ±30% of the indicated value with two significant figures. In another refinement, the subscript values can be rounded or truncated to ±20% of the indicated value with two significant figures.

[0051] As used herein, the term "and / or" means that all elements of the group may be present or only one element. For example, "A and / or B" means "only A, or only B, or A and B". In the case of "only A", the term also covers the possibility of the absence of B, i.e., "only A, but no B".

[0052] It is also to be understood that the present disclosure is not limited to the specific embodiments and methods described below, as the specific components and / or conditions can of course vary. Additionally, the terms used herein are for the purpose of describing only the specific embodiments of the present disclosure and are not intended to be limiting in any way.

[0053] The term "comprising" is synonymous with "including", "having", "containing", or "characterized by". These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps.

[0054] The phrase "consisting of" does not include any element, step, or ingredient not specified in the claim. When this phrase appears in a clause of the claim body, rather than immediately following the preamble, it only limits the elements recited in that clause; other elements are not excluded from the claim as a whole.

[0055] The phrase "consisting essentially of" limits the scope of the claim to the specified materials or steps and those that do not materially affect the basic and novel characteristics of the claimed subject matter.

[0056] Regarding the terms "comprising", "consisting of", and "consisting essentially of", when one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of one of the other two terms.

[0057] The term "one or more" means "at least one", and the term "at least one" means "one or more". The terms "one or more" and "at least one" include "multiple" as a subset.

[0058] Describing a group or class of materials as suitable for a given purpose in combination with one or more embodiments means that a mixture of any two or more members of that group or class is equally suitable. The chemical term description of an ingredient refers to the ingredient when added to any combination specified in the specification, and does not necessarily exclude chemical interactions among the ingredients of the mixture once mixed. The first definition of an acronym or other abbreviation applies to all subsequent uses of the same abbreviation in this document, with necessary modifications for normal grammatical variants of the abbreviated term as defined initially. Unless otherwise stated to the contrary, measurements of properties are made by the same technique for the same property as previously or subsequently involved.

[0059] Perhaps the most well-known metallic alloys are bronze and brass. Bronze was discovered and developed by multiple cultures at least 6,500 years ago. Similarly, various forms of brass have been known since ancient times around the world. Their applications are extensive, ranging from sculpture to coin making, mechanical and architectural applications.

[0060] Although the compositions of bronze and brass are different, a typical modern bronze is an alloy of copper and tin and contains approximately 88 weight percent copper (Cu) and 12 weight percent tin (Sn) based on the total weight of the bronze alloy. Brass is an alloy of copper and zinc (Zn) in various proportions. Due to their physical and / or mechanical properties, bronze and brass are more suitable for certain applications than other metals and alloys. The specific application in turn determines the specific composition of bronze and brass. Exemplary applications that utilize bronze and brass can be in hydraulics or technologies related to the conveyance of liquids through pipes and channels, particularly as a source of mechanical force or control. Non-limiting example applications, systems, or components include hydraulic actuators, cylinders, pistons, cables, presses, pumps. A non-limiting instance can be the axial piston for the Figure 1 hydraulic pump depicted in

[0061] In Figure 1 an axial piston pump assembly is shown. The piston pump 10 is a rotary device that uses the reciprocating piston principle to generate liquid flow. The piston pump 10 changes its displacement by varying the angle of the swashplate 12. The pump has more than one piston 14. The piston 14 and cylinder 20 assembly of the pump mechanism rotate with the drive shaft 16 to produce a reciprocating motion that draws fluid into the cylinder 20 from the inlet 18 via the port plate slot 22 and then discharges the fluid to the outlet 24 via the slot 22, generating flow.

[0062] In hydraulic applications, lead-containing brass and bronze have traditionally been used due to their high wear resistance, machinability, and atmospheric corrosion resistance. The machinability of brass and bronze can be improved by adding lead (Pb) as lead acts as a micro-chip breaker and a tool lubricant. Lead also provides pressure tightness by sealing shrinkage holes. For example, there are low, medium, and high lead brasses with lead contents up to approximately 3.5 weight percent.

[0063] Although lead-containing metal alloys have their advantages, federal and state governments have enacted regulations to limit human chemical exposure to lead. The main concern is the risk posed by the presence of lead in brass due to the potential (1) ingestion of brass particles / dust generated during grinding operations or machining processes and (2) inhalation of lead fumes from melting operations such as welding.

[0064] Accordingly, attempts have been made to develop lead-free brasses in which lead can be replaced by Si, Bi, or a combination of copper alloys (such as Zn, Fe, Ni, etc.). However, generally, even brasses labeled "lead-free" may contain trace amounts of lead; typically not exceeding 0.25% as defined by law.

[0065] In addition, Bi is one of the most likely candidate elements to replace toxic Pb in brass and bronze alloys. Although Bi can enhance the oxidation resistance of Cu-based metal alloys, Bi may segregate into separate microstructures because it is not very soluble. These brittle Bi impurities can cause fractures in copper-based metal alloys even in small amounts, which is undesirable.

[0066] Accordingly, there is still a need for copper-based alloys with low lead content (less than 3 wt%) or no lead, which simultaneously have excellent corrosion resistance, machinability, and other mechanical properties (such as wear resistance), and can be used to manufacture copper-based hydraulic components.

[0067] In one or more embodiments disclosed herein, a copper-based alloy is disclosed. The alloy may have a reduced Pb content compared to typical brass or bronze alloys used in hydraulic applications. Based on the total weight of the alloy, the reduced content may be less than or equal to 3 wt%. Based on the total weight of the alloy, the reduced content may be about, at most about, or not more than about 3.0, 2.9, 2.8, 2.7, 2.6, 2.5, 2.4, 2.3, 2.2, 2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.0 wt%. The alloy may be Pb-free. The alloy may be substantially Pb-free or contain at most 0.1 wt% of Pb based on the total weight of the alloy. Based on the total weight of the alloy, the alloy may contain at most 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, or 0.1 wt% of Pb.

[0068] The copper-based alloy may have the formula (I):

[0069] Cu a Sn b Zn c M d (I),

[0070] where

[0071] M is at least one transition metal, metalloid, or alkali metal,

[0072] a is any number between 0.50 and 0.93,

[0073] b is any number between 0.00 and 0.07, and

[0074] c is any number between 0.00 and 0.40, and

[0075] d is any number between 0.01 and 0.40.

[0076] In formula (I), M can be at least one element from the following groups of the periodic table: I.A, III.A, IV.A, V.A, VI.A, VI.B, VII.B, VIII.B. M can be a combination of more than two elements. M can be a combination of at most two, three, four, five or six elements. M can be Sb, Te, Co, Rb, Mo, In, W, Tl, Al, Fe, Mn, Ni, Pb, Si or a combination thereof. M can be at least one or a combination of at least two of Sb, Te, Co, Rb, Mo, In, W or Tl. M can be a combination of Al, Ni, Si and Fe.

[0077] In formula (I), a can be about, at least about, or at most about 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92 or 0.93. a can be any number between 0.50 and 0.93. a can be any range between two numbers disclosed herein.

[0078] In formula (I), b can be about, at least about, or at most about 0.00, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065 or 0.070. b can be any number between 0.00 and 0.07. b can be any range between two numbers disclosed herein.

[0079] In Formula (I), c can be about, at least about, or at most about 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, or 0.40. c can be any number between 0.00 and 0.40. c can be any range between two numbers disclosed herein.

[0080] In Formula (I), d can be about, at least about, or at most about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, or 0.40. d can be any number between 0.01 and 0.40. d can be any range between two numbers disclosed herein.

[0081] Non-limiting example alloys of formula (I) may include Cu 0.91 Sn 0.06 Co 0.04 , Cu 0.92 Sn 0.06 R 0.03 , Cu 0.92 Sn 0.06 Mo 0.02 , Cu 0.92 Sn 0.06 In 0.02 , Cu 0.93 Sn 0.06 Sb 0.02 , Cu 0.93 Sn 0.06 Te 0.02 , Cu 0.93 Sn 0.06 W 0.01 or Cu 0.93 Sn 0.06 Tl 0.01 Non-limiting example alloys of formula (I) may include Cu 0.57 Zn0.29 Al 0.07 Ni 0.04 Si 0.02 Fe 0.01 or Cu 0.57 Zn 0.29 (AlNiSiFe) 0.14 。

[0082] Based on the total weight of the alloy, the copper-based alloy may consist of, consist essentially of, contain, or comprise: at least about, more than about, or about 50 wt% of Cu; and

[0083] a compound having formula (II):

[0084] A x B y (II),

[0085] wherein

[0086] A is Cu, Sn, or Zn,

[0087] B is Co, Cr, In, Mn, Mo, Ni, Rb, Sb, Te, or Ti,

[0088] x is any number between 1 and 53, and

[0089] y is any number between 1 and 16.

[0090] In formula (II), B can be an element from the following groups of the periodic table: I.A, III. A, V.A, VI.A, IV.B, VI. B, VII. B, VIII. B. B can be a transition metal, a metalloid, or an alkali metal. B can be Co, In, or Ni.

[0091] In formula (II), x can be about, at least about, or at most about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, or 53. x can be any number between 1 and 53. x can be any range between two numbers disclosed herein.

[0092] In formula (II), y can be about, at least about, or at most about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16. y can be any number between 1 and 16. y can be any range between two numbers disclosed herein.

[0093] The compound can be an intermetallic compound. The alloy can include a compound of formula (II), at least one, one or more, or more than one compound of formula (II). The alloy can include a mixture of compounds of formula (II). The alloy can include 2, 3, 4, 5, 6, 7, 8, 9, 10, or more different compounds of formula (II), in the same or different amounts.

[0094] In a non-limiting example, the alloy can include different compounds of formula (II), each compound based on only one of Cu, Sn, or Zn. In a different embodiment, the alloy can include a first compound based on Cu, a second compound based on Sn, and a third compound based on Zn. In a non-limiting example, the alloy can include more than one compound of formula (II), each having the same A or B. For example, all compounds of formula (II) can have B = Ni. In another example, some compounds of formula (II) can have B = Ni, and some other compounds of formula (II) can have B = Co. The ratio of more than one compound of formula (II) in the alloy can be about, at least about, or at most about 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:1:1, 1:2:1, 1:2:2, 1:2:3, 1:5:7, and so on.

[0095] Non-limiting example alloys of formula (II) can include Cu7In, SnNi3, Sn4Ni3, Sn3Ni4, Sn2Ni3, SnNi3, SnCo, Sn3Co, Zn 53 Ni 16 、Zn 22 Ni3、Zn 11 Ni2、ZnNi、Zn 53 Co7、Zn 13 Co or Zn 11 Co2.

[0096] The alloy may comprise at least about 50 wt% of Cu. Based on the total weight of the alloy, the alloy may comprise about, at least about, or at most about 50 to 99, 52 to 80, or 54 to 70 wt% of Cu. Based on the total weight of the alloy, the alloy may comprise about, at least about, or at most about 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 96, 97, 98 or 99 wt% of Cu.

[0097] The alloy may comprise about, at most about, or no more than about 50 wt% of one or more compounds of formula (II). The alloy may comprise about, at most about, or no more than about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 wt% of one or more compounds of formula (II).

[0098] The alloy of formula (I) and / or (II) may further comprise an amount of elements Cr, Mn, Ti, Ni, Co or W, which may further improve the corrosion resistance and / or wear resistance of the alloy. Cr, Mn, Ti, Ni, Co or W may be dopants.

[0099] The alloy of formula (I) and (II) may have a K of about or at least about 70 to 304, 80 to 250, 90 to 200, or 100 to 164 GPa VRH value. The alloy of formula (I) and (II) may have a K of about or at least about 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300 or 305 GPa VRH value. The bulk modulus value K VRH is related to the wear resistance of the alloy.

[0100] The alloys of formula (I), (II), or combinations thereof can have a hardness of about or at least about 200 to 525, 220 to 480, or 250 to 450 HB. The alloys of formula (I), (II), or combinations thereof can have a hardness of about or at least about 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, or 525 HB.

[0101] A hydraulic component or system can include a first alloy of formula (I), a second alloy of formula (II), or both. The hydraulic component or system can be an axial piston pump. The first and second alloys can be included in a ratio of first alloy:second alloy or second alloy:first alloy of about 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:15, 1:20, 1:25, 1:50, 1:75, 1:100. The first and / or second alloys can be included in single-phase, phase-separated, or precipitate forms.

[0102] Methods for identifying materials of formula (I) and (II) are disclosed herein. The methods are described in the experimental section below. The alloys of formula (I) and (II) can be prepared by conventional methods used to prepare copper-based alloys such as bronzes and brasses, e.g., by alloying the metals and casting them into ingots, then melting the copper and adding the alloy to the molten copper. Other methods for making the alloys of formula (I) and (II) are envisioned.

[0103] Experimental Section

[0104] Examples 1 - 3

[0105] To identify viable candidate alloys, three different Cu-based alloys - Examples 1 - 3 were tested. The first alloy was Pb-containing HF2, which typically includes Pb (9 - 11 wt%), Sn (9 - 11 wt%), Cu (balance). For HF2, the following formula was used in Example 1: Cu 0.9 Sn 0.06 Pb 0.04。The second alloy is Pb-free KSH or KSH with a reduced amount of Pb, typically including Cu (55 – 65 wt%), Si (0.1 – 1.5 wt%), Al (2.5 – 5 wt%), Ni (2.5 – 4.5 wt%), Fe (0.5– 1.5 wt%), Pb (<0.1 wt%), Zn (balance). For the KSH of Example 2, the following formula is used: Cu 0.57 Zn 0.29 Al 0.07 Ni 0.0 4Si 0.02 Fe 0.01 。The third alloy is Bi-substituted CuSn 10 Bi3: typically including Sn (9 – 11 wt%), Bi (2.8 – 3.6 wt%), Cu (balance). For the Bi-substituted CuSn of Example 3 10 Bi3, the following chemical formula is used: Cu 0.93 Sn 0.06 Bi 0.01 。

[0106] (I)Thermodynamic Phase Stability

[0107] Analyze the chemical space of each test alloy in contact with oxygen to evaluate the interaction of each alloy with air. Use the phase diagrams generated in the public database oqmd.org and density functional theory (DFT) calculations based on T = 0K to identify the chemical space. All possible phases that can form in the chemical space of the corresponding alloy are identified in Tables 1-3 below.

[0108] (a) Chemical space of Pb-containing HF2, Example 1

[0109] The chemical space of Example 1 is a 4D chemical space of three metal elements in contact with O2. The 4D phase diagram generated in the public database oqmd.org depicting the phase equilibrium data is shown in Figure 2A . This phase diagram shows the stable compounds at T = 0K as a point, and each line corresponds to a two-phase equilibrium in the diagram.

[0110] Since brass or bronze metal alloys can be heat-treated at high temperatures, all compounds that can become stable up to 1300 °C were analyzed. A list of the identified compounds related to the Cu-Pb-Sn-O chemical space of Example 1 is provided in Table 1. The stability of the identified compounds was classified as stable or near-stable compounds. Since DFT calculations are based on T = 0K thermodynamics, stable compounds are based on T = 0K stability. The "near-stable" compounds were classified as compounds that become stable near ambient temperature (temperatures up to 25 °C) or up to the temperature associated with any metal heat-treatment condition (with an upper limit set at a maximum of 1300 °C). Table 1 below shows all possible phases that can form in the Cu-Pb-Sn-O chemical space of Example 1, depending on the oxidation / reduction conditions and local concentration / segregation of the elements in the metal alloy.

[0111] Table 1 - Stable and near-stable compounds in the Cu-Pb-Sn-O chemical space, related to the Pb-containing HF2 bronze metal (Cu, Pb, Sn) and air (O) of Example 1

[0112]

[0113] The same analysis was performed for the second and third embodiments.

[0114] (b) Chemical space of KSH without Pb or with reduced Pb content, Example 2

[0115] As described above for Example 1, a 7-dimensional chemical space of six metals (Cu, Zn, Al, Ni, Si, Fe) in contact with oxygen was generated. Figure 2B A 7-dimensional phase diagram was depicted, which helps to understand the interaction between the KSR metal and air. Table 2 below summarizes the list of related compounds in this chemical space.

[0116] Table 2 - Stable and near-stable compounds in the Cu-Zn-Al-Ni-Si-Fe-O chemical space, related to the KSH brass metal alloy of Example 2 in contact with O2

[0117]

[0118] (c) Chemical space of Bi-substituted CuSn10Bi3, Example 3

[0119] As described above for Examples 1 and 2, a 4-dimensional chemical space of three metal elements (Cu, Sn, and Fe) in contact with oxygen was generated. Figure 2CDepicts a 4D phase diagram, which helps to understand the interaction between the Bi-substituted CuSn10Bi3 metal of Example 3 and air. Table 3 below summarizes the list of related compounds in this chemical space.

[0120] Table 3 - Stable and near-stable compounds in the Cu-Sn-Bi-O chemical space, related to the Bi-substituted brass metal (CuSn10Bi3) of Example 3 in contact with air (O2)

[0121]

[0122] (II)Corrosion Resistance or O 2 Chemical Tolerance

[0123] The chemical tolerance of each example to O2 was examined. For this analysis, the "Interface Reactions" module suite publicly available on materialsproject.org was used. This analysis focused on testing the reaction between the alloy and O2 under the following conditions.

[0124] i） When there is a dilute amount of O2, and

[0125] ii) During the most thermodynamically stable reaction pathway (i.e., at its minimum reaction enthalpy in the 2D phase space between the Cu-based metal alloy and O2).

[0126] Figure 3 The phase diagram generated between O2 and Example 1 is shown. In Figure 3 , the mole fraction (x) represents the amounts of O2 and the HF2 metal. For example, when x = 0, it will be pure HF2 metal; when x = 1, it will be 100% O2 gas. As can be seen from Figure 3 , the first decomposition reaction of the HF2 metal (shown as Reaction 1 in Figure 3 ) occurs at a mole fraction x = 0.029, where 0.029O2 reacts with 0.971Cu 0.9 Sn 0.06 Pb 0.04 to form 0.874Cu, 0.039Pb, and 0.058SnO as decomposition products. In Figure 3 , the reaction enthalpy of Reaction 1 ( E Rxn ) between O2 and the HF2 metal is found to be -0.184 eV / atom.

[0127] The most stable reaction between the two species occurs at Reaction 2 (i.e., the minimum E rxn). The evaluation of Reaction 2 considered the situation where both a large amount of O2 gas and Cu alloy metal were present, and the decomposition reaction could occur at the minimum reaction enthalpy (i.e., the most favorable conditions). For all Cu alloy metals, comparisons with HF2 were made at Reactions 1 and 2.

[0128] It is desirable that the reaction of the Cu alloy metal with O2 be as little as possible. For example, if two O2 molecules react with one Cu alloy candidate and another Cu alloy composition can react with only one O2 gas molecule, it can be concluded that under the same corrosion conditions, the latter Cu alloy composition can provide twice the protection against oxidation compared to the former composition. The reaction enthalpy ( E rxn ) describes how favorable a certain reaction is. Therefore, in order to make the Cu alloy oxidation decomposition reaction occur less favorably, reactions with higher E rxn values were identified. For example, when E rxn is -0.2 eV / atom, the corresponding decomposition reaction is less favorable compared to the case when E rxn is -0.4 eV / atom, which is desirable. Overall, an ideal Cu alloy candidate is configured to react with O2 as little as possible and at the same time have a relatively high E rxn composition.

[0129] Tables 4 and 5 summarize the chemical reactivity of Examples 1, 2, and 3 with O2 gas (i.e., Reaction 1) at the corresponding dilution amounts of O2 and the corresponding most stable thermodynamic reaction between the O2 gas and the Cu metal alloy (i.e., E rxn,min Reaction 2 at ). In Tables 4 and 5, the molar ratio between O2 and the Cu alloy metal and its reaction enthalpy ( E rxn,dil. ) are provided for each reaction.

[0130] Table 4 - Chemical Reactivity of Examples 1 - 3 with Diluted O2 Gas

[0131] Example <![CDATA[Decomposition reaction at diluted concentration of O2]]> <![CDATA[O2 / Metal]]> <![CDATA E rxn,dil. [eV / atom] <!-- 10 -->]]> 1 <![CDATA[0.029 O2 + 0.971 Cu 0.9 Sn 0.06 Pb 0.04 → 0.874 Cu + 0.039 Pb + 0.058 SnO]]> 0.037 -0.184 2 <![CDATA[0.036 O2 + 0.964 Al 0.07 Zn 0.29 Fe 0.01 Cu 0.57 Si 0.02 Ni 0.04 → 0.035 Zn8Cu5 + 0.01 SiNi2 + 0.01FeSi + 0.019 AlNi + 0.024 Al2O3 + 0.375 Cu]]> 0.030 -0.366 3 <![CDATA[0.029 O2 + 0.971 Cu 0.93 Sn 0.06 Bi 0.01 → 0.058 SnO + 0.903 Cu + 0.01 Bi]]> 0.127 -0.184

[0132] Table 5 – Chemical Reactivity of Examples 1 - 3, where E rxn is the minimum (i.e., the most stable decomposition reaction)

[0133] Example <![CDATA E rxn,min the most stable oxidation reaction]]> <![CDATA[O2 / Metal]]> <![CDATA E rxn,min. [eV / atom]]]> Final Evaluation 1 <![CDATA[0.355 O2 + 0.645 Cu 0.9 Sn 0.06 Pb 0.04 → 0.026 Cu6PbO8 + 0.039SnO2 + 0.426 CuO]]> 0.550 -1.082 <![CDATA[Highest protection for O2]]> 2 <![CDATA[0.346 O2 + 0.654 Al 0.07 Zn 0.29 Fe 0.01 Cu 0.57 Si 0.02 Ni 0.04 → 0.373 CuO+ 0.013 Zn2SiO4 + 0.023 Al2ZnO4 + 0.003 Fe2NiO4 + 0.141 ZnO+ 0.023 NiO]]> 0.529 -1.426 <![CDATA[Less protective of O2 than HF2 (by about 30%)]]> 3 <![CDATA[0.347 O2 + 0.653 Cu 0.93 Sn 0.06 Bi 0.01 → 0.607 CuO + 0.003Sn2Bi2O7 + 0.033 SnO2]]> 0.531 -1.065 <![CDATA[Similar to HF2]]>

[0134] As can be seen in Tables 4 and 5, Examples 1 and 3 are similar in terms of evaluating the oxidation corrosion tendency of the molar ratio and reaction enthalpy data. Therefore, Example 3 can achieve antioxidant properties similar to those of the leaded bronze metal alloy tested in Example 1. In contrast, the brass alloy containing Al, Z, Fe, Si, and Ni in Example 2 has a probability of oxidation approximately 30% higher than that in Example 1.

[0135] (III)Mechanical Properties

[0136] The mechanical properties of Examples 1 - 3 were measured and evaluated.

[0137] Hardness is generally used as a criterion for judging alloys, castings, hard - facings, and overlays in the field of wear resistance. Generally, it is understood that the harder the material, the higher the wear resistance. The hardness of a material also tends to increase with the increase in the elastic modulus.

[0138] There are three different elastic moduli: Young's modulus, shear modulus, and bulk modulus. Young's modulus is a mechanical property that measures the stiffness of solid materials. It defines the relationship between stress (force per unit area) and strain (proportional deformation) in the linear elastic state of uniaxial deformation of the material. The shear modulus is defined as the ratio of shear stress to shear strain. The bulk modulus is an extension of Young's modulus to three dimensions.

[0139] The calculated bulk modulus values are used as key descriptors related to wear resistance. A high bulk modulus (which is proportional to hardness) means higher wear resistance of the material. Table 6 shows the average bulk modulus (K VRH ) values: that is, the average of K R (Reuss bulk modulus - the lower limit of polycrystalline materials) and K V (Voigt bulk modulus - the upper limit of polycrystalline materials). The data was evaluated using Scientific Data , 2:150009, DOI: 10.1038 / sdata.2015.9 and materialsproject.org. As can be seen from Table 6, Bi has a lower bulk modulus value than Pb, while many elements (Zn, Al, Si, Fe, and Ni) contained in KSH have higher bulk modulus values than Pb.

[0140] Table 6 - Calculated bulk modulus K of the chemical elements of the brass / bronze alloy metals of Examples 1 - 3 VRH

[0141] Element Ni Fe Cu Si Al Zn Sn Pb Bi <![CDATA[K VRH [GPa]]]> 198 192 145 83 83 67 38 37 29

[0142] Taken from Glass and Ceramics, the data of Volume 76, Issues 1–2, May 2019 (Russian Original, Issues 1–2, January–February 2019) were used to confirm that materials with higher values of bulk modulus tend to have better wear resistance.

[0143] Table 7 – Calculated bulk modulus K of various coatings tested in Glass and Ceramics the Figure 1 of VRH

[0144] Figure 1 Sample number in Material <![CDATA[K VRH [GPa]]]> , Figure 1 wear resistance in 8) Diamond 436 Best 5) <![CDATA[TiO2]]> 209 Second Best 4) <![CDATA[B4C]]> 227 Third 2) <![CDATA[Cr2O3]]> 203 Fourth 7) TiN 259 Fifth 3) <![CDATA[Al2O3]]> 232 Sixth 6) <![CDATA[ZrO2]]> 183 Worst

[0145] The bulk modulus of each material in Table 7 was tested. A strong correlation between the bulk modulus and wear resistance was determined. For example, among the test samples, ZrO2 with the lowest K VRH value resulted in the worst wear resistance. A value of K VRH > 200 GPa was associated with good wear resistance.

[0146] Examples 1–3 were analyzed by calculating the K VRH value, excluding Cu, Sn, and Zn. The exclusions were made to provide an understanding of the influence of minor elements, except for Cu and Sn in bronze and Cu and Zn in brass. Clearly, for Example 1, this translated to the K VRH value of Pb; and, for Example 3, this was the same as the K VRH value of Bi. In Table 8 below, it is clearly shown that Examples 1 and 3 have similar K VRH ranges, namely 29 and 37 GPa, respectively. In contrast, the K VRH of Example 2 was higher because the K VRH values of Ni, Fe, Si, and Al were higher. Therefore, it was found that the composition of Example 2 did not result in significant cracking.

[0147] Table 8 – Calculated K VRH values for Examples 1–3

[0148] Example Number Composition <![CDATA[K calculated excluding Cu, Zn, Sn VRH [GPa]]]> Remarks 1 <![CDATA[Copper 0.9 Tin 0.06 Lead 0.04 > 37 Pb 2 <![CDATA[Cu 0.57 Zn 0.29 Al 0.07 Ni 0.04 Si 0.02 Fe 0.01 > 123 Ni, Fe, Si, Al 3 <![CDATA[Copper 0.93 Tin 0.06 Bismuth 0.01 > 29 Bi

[0149] Therefore, although Example 3 has a similar O2 corrosion resistance to Example 1 (see Tables 4–5), among the different chemical elements examined, the bulk modulus value of Bi is lower than that of Pb, indicating an increased level of brittleness of Bi, which may lead to cracking and material failure.

[0150] The calculated data were confirmed by observing the fabricated distribution plates made of the materials of Examples 1–3. The distribution plate of Example 3 is shown in Figure 4AIn the middle, the same distribution plates were fabricated for Examples 1 and 2. It was observed that the distribution plate of Example 3 had multiple cracks in Region B. Figure 4B shows a backscattered electron imaging (BEI) image, where several bright spots correspond to Bi-rich precipitates. BEI was used to direct the electron beam to Figure 4A the relevant regions near the cracks in the cladding in. The advantage of backscattered electrons is that they are sensitive to the atomic mass of the atomic nuclei from which they are scattered. Thus, in the BEI image, the heavier elements that are scattered more efficiently appear brighter than the lighter elements. The insoluble, brittle Bi impurities in Example 3 caused mechanical failures in the fabricated distribution plates of Example 3. In contrast, the distribution plates made of the material of Example 2 (where Pb is more soluble in the metal alloy) did not have any obvious cracks. Example 1 also did not show any cracks during the test.

[0151] Then, the K of the more stable phase mixture was calculated based on the analysis shown above. VRH values. For example, in Example 2, the K VRH values of SiNi2, FeSi, and AlNi were evaluated to be 193, 211, and 162 GPa, respectively. It was evaluated that the results in Tables 8 and 9 were consistent: namely, the K VRH of Examples 1 and 3 was lower than that of Example 2. The K of additional stable phase mixtures is provided in Table 9. VRH values.

[0152] Table 9 – K values calculated for Cu-based alloys based on decomposition reactions VRH values

[0153] Example Number Decomposition <![CDATA[K other than Cu-containing, Zn-containing and Sn-containing species]]> VRH [GPa]]]> Remarks 1 0.06 CuSn + 0.84 Cu + 0.04 Pb 37 Pb 2 <![CDATA[0.036 Zn8Cu5 + 0.05 AlCu3 + 0.01 SiNi2 + 0.01 FeSi + 0.02 AlNi + 0.239Cu]]> 182 <![CDATA[SiNi2, FeSi, AlNi]]> 3 0.06 CuSn + 0.87 Cu + 0.01 Bi 29 Bi

[0154] The hardness ranges of Examples 1 - 3 measured experimentally and found in the literature are provided in Table 10. The lower K VRH is associated with lower hardness measurements.

[0155] Table 10 – Measured hardness of Examples 1 - 3 compared with the K VRH values of Tables 8 and 9

[0156] Example Number Hardness Range (HB) <![CDATA[K in Table 8 VRH,除Cu,Zn,Sn外 [GPa]]]> <![CDATA[K in Table 9 VRH,除Cu-,Zn-,Sn-外 [GPa)]]]> 1 70 – 100 37 37 2 200 – 220 123 182 3 90 – 120 29 29

[0157] In summary, it was found that although Bi helps to improve corrosion resistance, Bi may not directly contribute to wear resistance because Bi segregates / precipitates and is brittle. This was also confirmed in the literature such as Hsieh et al. It was reported that when different Bi contents of 0.5, 1, and 1.5 wt% were added, significant changes occurred in the brass metal. Met. Mater. Int., 19, Issue 6 (2013), pp. 1173 - 1179). It is reported that Bi precipitation may result in discontinuous globular (<1 μm), discoid (about 1 μm), block (>1 μm), or continuous massive structures (about 20 to 30 μm) in brass alloys.

[0158] Additional Example

[0159] (IV)Brass / Bronze Material Design and Discovery for Hydraulics

[0160] Since Bi is recognized as a non - ideal candidate to replace Pb due to its brittleness, the O2 corrosion resistance of elements other than Bi was evaluated. Cu - based alloys with 3 wt% dopant, 10 wt% Sn, and the balance Cu, similar to CuSn10Bi3, were selected.

[0161] Due to the different atomic masses of different elements, the possible chemical formulas for Cu 0.86 Sn 0.05 M 0.08 - Cu 0.93 Sn 0.06 M 0.01 unequal were studied. The following chemical elements M were tested: Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, In, Sb, Te, Ba, La, Ce, Hf, Ta, W, Tl, Pb, and Bi. The O2 gas reaction under the most stable thermodynamic reaction was examined (@ E rxn ). As shown in Table 11, M = Ni, Sb, Te, Co, Rb, Mo, In, W, or Tl is more oxidation - resistant than Bi. Specifically, when added at 3 wt% to the Cu - Sn bronze alloy metal system, Ni, Sb, and Te were determined to be the most oxidation - resistant elements. Alkali metals were excluded due to their ductility.

[0162] Table 11 - Chemical elements more oxidation - resistant than Pb and Bi

[0163] Equation <![CDATA[The most stable O2 reaction]]> <![CDATA[O2 / Brass]]> <![CDATA E rxn (eV / atom)]]> Remarks <![CDATA[Copper 0.91 Tin 0.06 Cobalt 0.04 > <![CDATA[0.351 O2 + 0.649 Co 0.04 Cu 0.91 Sn 0.06 → 0.009 Co3O4 + 0.039 SnO2 +0.59 CuO]]> 0.541 -1.072 Better than Bi <![CDATA[Cu 0.91 Sn 0.06 Ni 0.04 > <![CDATA[0.349 O2 + 0.651 Cu 0.91 Ni 0.04 Sn 0.06 → 0.593 CuO + 0.039 SnO2 +0.026 NiO]]> 0.536 -1.045 Better than Pb <![CDATA[Cu 0.92 Sn 0.06 Rb 0.03 > <![CDATA[0.349 O2 + 0.651 Rb 0.03 Cu 0.92 Sn 0.06 → 0.02 RbCuO2 + 0.039 SnO2 +0.58 CuO]]> 0.536 -1.071 Better than Bi <![CDATA[Cu 0.92 Sn 0.06 Mo 0.02 > <![CDATA[0.355 O2 + 0.645 Cu 0.92 Sn 0.06 Mo 0.02 → 0.013 MoO3 + 0.594 CuO +0.039 SnO2]]> 0.550 -1.095 Better than Bi <![CDATA[Cu 0.92 Sn 0.06 In 0.02 > <![CDATA[0.351 O2 + 0.649 In 0.02 Cu 0.92 Sn 0.06 → 0.013 In(Cu3O4)2 + 0.039 SnO2+ 0.519 CuO]]> 0.541 -1.082 Better than Bi <![CDATA[Cu 0.93 Sn 0.06 Sb 0.02 > <![CDATA[0.355 O2 + 0.645 Cu 0.93 Sn 0.06 Sb 0.02 → 0.006 Cu(SbO3)2 + 0.594 CuO +0.039 SnO2]]> 0.550 -1.083 Better than Pb <![CDATA[Cu 0.93 Sn 0.06 Te 0.02 > <![CDATA[0.357 O2 + 0.643 Cu 0.93 Sn 0.06 Te 0.02 → 0.013 CuTeO4 + 0.585 CuO +0.039 SnO2]]> 0.555 -1.065 Better than Pb <![CDATA[Cu 0.93 Sn 0.06 W 0. 01 > <![CDATA[0.351 O2 + 0.649 Cu 0.93 Sn 0.06 W 0.01 → 0.006 WO3 + 0.604 CuO + 0.039SnO2]]> 0.541 -1.079 Better than Bi <![CDATA[Cu 0.93 Sn 0.06 Tl 0.01 > <![CDATA[0.347 O2 + 0.653 Tl 0.01 Cu 0.93 Sn 0.06 → 0.039 SnO2 + 0.003 Tl2O3 +0.607 CuO]]> 0.531 -1.058 Better than Bi <![CDATA[Copper 0.93 Tin 0.06 Lead 0.01 > <![CDATA[0.349 O2 + 0.651 Cu 0.93 Sn 0.06 Pb 0.01 → 0.007 Cu6PbO8 + 0.039 SnO2 +0.567 CuO]]> 0.536 -1.062 Better than Bi <![CDATA[Copper 0.93 Tin 0.06 Bismuth 0.01 > <![CDATA[0.347 O2 + 0.653 Cu 0.93 Sn 0.06 Bi 0.01 → 0.607 CuO + 0.003 Sn2Bi2O7 +0.033 SnO2]]> 0.531 -1.065 Reference

[0164] Fe, Al, Si, Mn, Zn, Ti, Sb, Cr, and Ni are equivalent to or cheaper than Bi in terms of element cost and abundance. Table 12 below shows the calculated bulk modulus K VRH values. As observed in Example 2, compared with Example 1 and Example 3, Ni, Fe, Si, Al, and Zn, as well as the intermetallic compounds listed in Table 2, result in improved wear resistance and have very high K VRH values.

[0165] Table 12 - Calculated Bulk Modulus K VRH and Hardness

[0166] Element Cr Ni Fe Mn Ti Al So Zn Sb <![CDATA[K VRH [GPa]]]> 259 198 182 180 113 83 83 67 36 Hardness [HB]* 332 208 145 58 212 73 N / A 122 87

[0167] *Collected from https: / / periodictable.com / Properties / A / BrinellHardness.v.log.wt.html; converted from MPa to HB.

[0168] Subsequently, it was determined that Ti can form many different intermetallic compounds with Cu, Sn, or Zn, which also have high K VRH values. In addition, Mn can form an intermetallic compound with Zn (used in bronze alloys). Cr does not have intermetallic compounds, but Cr metal or Cr2O3 - both of these materials have high K VRH values - may contribute to improving wear resistance.

[0169] Table 13 - List of Stable Intermetallic Compounds in the Cu-Sn-Zn-Cr-Mn-Ti Chemical Space

[0170]

[0171] a Evaluated by Jun Ikeda et al., Precipitation Behavior and Properties of Cu-Ti Alloys with Added Nitrogen, MATERIALS TRANSACTIONS, Online ISSN: 1347-5320, based on Cu-Ti alloys

[0172] b Evaluated by Haozhong Xiao et al., Microstructure and mechanical properties of vacuum brazed CBN abrasive segments with tungsten carbide reinforced Cu–Sn–Ti alloys, Ceramics International, Vol. 45, No. 9, June 15, 2019, pp. 12469-12475, based on Cu-Sn-Ti alloys

[0173] cChih-Ting Wu et al., Effects of Mn, Zn Additions and Cooling Rate on Mechanical and Corrosion Properties of Al-4.6Mg Casting Alloys, Materials (Basel). Apr 2020; 13(8): 1983, published online Apr 24, 2020. doi: 10.3390 / ma13081983, based on Zn-Mn-Al-Mg alloys

[0174] d Jixing Lin et al., A biodegradable Zn-1Cu-0.1Ti alloy with antibacterial properties for orthopedic applications, Acta Biomaterialia, Volume 106, April 1, 2020, pp. 410-427, based on Cu-Zn-Ti alloys.

[0175] In addition, some chemical elements were predicted in Table 14 to improve atmospheric corrosion resistance. Since relatively opposite behaviors were observed between oxidation and wear resistance, Cu, Sn, Zn-M intermetallic compounds with high K VRH values were studied, which might be available for both degradation modes.

[0176] It was also found that pure elements with high K VRH values (such as Ni, Co, and W) are corrosion-resistant. Many different stable intermetallic compounds were identified in Table 14, including Ni, Sb, Te, Co, Rb, Mo, In, W, and Tl with oxidant tolerance, which can form stable compounds with Cu, Sn, Zn. When added to Cu-based alloys, this intermetallic compound can address oxidation and wear resistance from a material perspective (the best candidates are shown in bold in Table 14). The hardness ranges of the elements and intermetallic compounds are listed in Table 14. Since the hardness values of not all compounds are available, for the unavailable compounds, the value was evaluated based on literature values.

[0177] Table 14 - K of elements predicted to be corrosion-resistant to O2 VRH

[0178]

[0179] **Element hardness is collected from Brinell Hardness of the elements, https: / / periodictable.com / Properties / A / BrinellHardness.v.log.wt.html

[0180] a Jin, Y., Cho, J., Park, D. et al. . Manufacturing and MacroscopicProperties of Cold Sprayed Cu-In Coating Material for Sputtering Target. J Therm Spray Tech 20, 497–507 (2011). https: / / doi.org / 10.1007 / s11666-010-9552-6

[0181] b Scientific Letters of Rzeszow University of Technology, NR 293 (e-ISSN 2300-5211), Mechanika, Kwartalnik tom XXXIII zezyt 88 (nr 2 / 2016)kwiecień-czerwiec (not exactly composed, but the highest Sn added to Ni is 12 wt% Sn)

[0182] c Evaluated by N. Tamura et al., Mechanical Stability of Sn–Co alloy anodes forlithium secondary batteries, Electrochemical Acta, Vol. 49, No. 12, May 15, 2004, pp. 1949-1956, based on Sn-Co alloy

[0183] dEvaluated by R. M. Gnanamuthu et al., Comparative study on structure, corrosion and hardness of Zn–Ni alloy deposition on AISI 347 steel aircraft material, Journal of Alloys and Compounds, Vol. 513, February 5, 2012, pp. 449-454, based on Zn-Ni alloy

[0184] e By Stone, H.E.N., The oxidation resistance and hardness of some intermetallic compounds. J Mater Sci Evaluated in 9, 607–613 (1974), based on Zn-Co alloy.

[0185] While the exemplary embodiments described above are not intended to describe all possible forms covered by the claims, the words used in the specification are descriptive rather than limiting, and it should be understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously mentioned, the features of various embodiments may be combined to form other embodiments of the disclosure that may not be explicitly described or illustrated. Although various embodiments may be described as providing advantages or being preferred over other embodiments or prior art implementations in one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve the desired overall system attributes, depending on the particular application and implementation. These attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, suitability, weight, manufacturability, ease of assembly, etc. Thus, to the extent that any embodiment is described as less desirable than other embodiments or prior art implementations in one or more characteristics, these embodiments are not outside the scope of the disclosure and may be desirable for a particular application.

Claims

1. A wear-resistant hydraulic system, comprising: A first copper-based alloy having the formula (I): Cu a Sn b Zn c M d (I), and A second copper-based alloy, comprising: At least 50 wt% of Cu, based on the total weight of the alloy; and At least one compound of formula (II): A x B y (II), wherein the first copper-based alloy is Cu 0.91 Sn 0.06 Co 0.04 、Cu 0.92 Sn 0.06 Rb 0.03 、Cu 0.92 Sn 0.06 Mo 0.02 、Cu 0.92 Sn 0.06 In 0.02 、Cu 0.93 Sn 0.06 Sb 0.02 、Cu 0.93 Sn 0.06 Te 0.02 、Cu 0.93 Sn 0.06 W 0.01 or Cu 0.93 Sn 0.06 Tl 0.01 ,and the at least one compound of formula (II) is Cu7In, SnCo, Sn3Co, Zn 53 Co7, Zn 13 Co or Zn 11 Co2, wherein the first or second alloy has a bulk modulus K in the range of 70 to 304 GPa VRH value.

2. The hydraulic system of claim 1, wherein the hydraulic system includes an axial piston pump.

3. A copper-based alloy, comprising: At least 50 wt% of Cu, based on the total weight of the alloy; and At least one compound of formula (II): A x B y (II), wherein the at least one compound of formula (II) is Cu7In, SnCo, Sn3Co, Zn 53 Co7, Zn 13 Co or Zn 11 Co2.

4. The copper-based alloy of claim 3, wherein the at least one compound of formula (II) comprises two different compounds.

5. The copper-based alloy of claim 3, wherein the alloy has a bulk modulus K VRH value of 70 to 304 GPa.

6. The copper-based alloy of claim 3, wherein the at least one compound of formula (II) comprises a mixture of compounds, wherein at least one has A = Sn and wherein at least one has A = Zn.

7. A copper-based alloy having the formula (I): Cu a Sn b Zn c M d (I), wherein the alloy is Cu 0.91 Sn 0.06 Co 0.04 、Cu 0.92 Sn 0.06 Rb 0.03 、Cu 0.92 Sn 0.06 Mo 0.02 、Cu 0.92 Sn 0.06 In 0.02 、Cu 0.93 Sn 0.06 Sb 0.02 、Cu 0.93 Sn 0.06 Te 0.02 、Cu 0.93 Sn 0.06 W 0.01 or Cu 0.93 Sn 0.06 Tl 0.01 。 8. The copper-based alloy of claim 7, wherein the alloy has a bulk modulus K VRH value of 70 to 304 GPa.

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