Method for making metal matrix composite strip products - Patent Application 20070122997

Abstract

A method for producing coiled strip of metal matrix composite (MMC) material is disclosed. The method involves a combination of hot rolling and warm rolling processes that reduce the thickness of the input material and increase its ductility. The resulting MMC strip can be wound into a coil, which is useful for high-volume coil-to-coil applications. [Selected Figure] Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 668,434, filed May 8, 2018, the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates to a method for processing metal matrix composites (MMCs). In particular, this process allows MMC materials to be fabricated as coilable strips. This process is particularly useful with aluminum-silicon carbide (Al-SiC) metal matrix composites, which contain silicon carbide particles dispersed in an aluminum alloy matrix. Also disclosed are coils of MMC material and methods for making such coils, articles formed from such coilable strip material, and methods for making such articles. [Background technology]

[0003]

[0003] Metal matrix composite (MMC) materials exhibit exceptional stiffness, high strength, high fatigue strength, high tensile strength at elevated temperatures, and wear resistance. However, these materials have limited ductility, and therefore articles made from such materials are primarily produced by batch processes. It would be desirable to provide MMC materials in a form that allows for high-volume processing using automated processing equipment. Summary of the Invention [Means for solving the problem]

[0004] This disclosure relates to a method for processing metal matrix composite (MMC) materials so that they can be coiled into strip. This processing reduces the strength of the MMC but increases its ductility to prevent cracking that limits the ability to economically produce thin gauge coilable strip.

[0005]

[0005] In various embodiments, the present specification discloses a method for producing a strip of MMC material, the method including hot working a rectangular input of metal matrix composite (MMC) material to produce a hot-rolled MMC material, and warm working the hot-rolled MMC material to obtain a strip of MMC material.

[0006] The strip of MMC material can then be wound into a coil.

[0007] In some embodiments, the hot working is performed at a temperature above the recrystallization temperature of the MMC material. In other embodiments, the hot working may be performed at a temperature of about 900°F (482°C) or greater. The hot working may be performed to a total %HW of at least 75%. The hot working may be performed in multiple hot passes, with each hot pass resulting in a %HW of 20% or less.

[0007]

[0008] Warm working can be performed at a temperature above room temperature and below the recrystallization temperature of the MMC material. In certain embodiments, warm working can be performed at a temperature of about 350°F to about 600°F (about 177°C to about 315°C). Warm working can be performed using heated rollers. Warm working can be performed to a total %WW of at least 75%. Warm working can be performed in multiple warm passes, with each warm pass resulting in a %WW of 65% or less.

[0008]

[0009] In a further embodiment, the strip of MMC material is also cold worked after warm working, which may be to a total %CW of about 10% or less.

[0010] The MMC material includes an aluminum alloy and ceramic particles dispersed in the aluminum alloy. The ceramic particles may include at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides, and in certain embodiments, is silicon carbide. The MMC material may include about 15 vol% to about 50 vol% of the ceramic particles. The average particle size of the ceramic particles is about 0.3 micrometer ~about 5 micrometer It could be.

[0009]

[0011] In certain embodiments, the MMC material is a 6061 or 2124 aluminum alloy reinforced with about 15 vol% to about 50 vol% silicon carbide. In other embodiments, the MMC material is a 6061, 6063, 6082, 2009, 2618, or 2124 aluminum alloy reinforced with about 10 vol% to about 50 vol% silicon carbide. Of course, other ceramic particles may be used in place of or in addition to silicon carbide.

[0010]

[0012] Also disclosed herein are coiled strips of metal matrix composite (MMC) material made according to the above methods, and articles made from uncoiled strips of metal matrix composite (MMC) material.

[0011]

[0013] These and other non-limiting features of the present disclosure are more particularly disclosed below.

[0014] The following is a brief description of the drawings, which are presented for purposes of illustration, but not limitation, of representative embodiments disclosed herein. [Brief explanation of the drawings]

[0012] [Figure 1]

[0015] 1 is a diagram illustrating an exemplary process according to some embodiments of the present disclosure. [Figure 2]

[0016] FIG. 1 is a diagram of a wound coil made in accordance with some embodiments of the present disclosure. [Figure 3A]

[0017] Photograph of a short strip of MMC material that has only been cold worked. The strip shows crack initiation. [Figure 3B] Figure 3B is a photograph of a short strip of MMC material that has only been cold worked, showing crack initiation. [Figure 4]

[0018] 1 is a photograph of a strip of material processed in accordance with some embodiments of the present disclosure and having enhanced properties. [Figure 5]

[0019] 1 is a photograph of coiled strip exiting the apparatus used for warm rolling. DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0020] The components, processes, and apparatus disclosed herein can be more fully understood by reference to the accompanying drawings, which are merely schematic illustrations based on convenience and ease of illustrating the disclosure, and are therefore not intended to illustrate the relative size and dimensions of the apparatus or its components, and / or to define or limit the scope of the exemplary embodiments.

[0014]

[0021] Although specific terminology is used in the following description for the sake of clarity, these terms are intended to refer only to the particular configurations of the embodiments selected for illustration in the drawings and are not intended to define or limit the scope of the present disclosure. In the drawings and the following description, like numerical designations should be understood to refer to components of similar function.

[0015]

[0022] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0023] As used in this specification and claims, the term "comprising" can encompass "consisting of" and "consisting essentially of" embodiments. The terms "comprise," "include," "having," "has," "can," "contain," and variations thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients / components / steps and permit the presence of other ingredients / components / steps. However, such descriptions should also be understood to describe compositions, articles, or processes that "consist of" and "consist essentially of" the listed ingredients / components / steps, which descriptions permit the inclusion of only the named ingredients / components / steps along with impurities that may result therefrom, and to the exclusion of other ingredients / components / steps.

[0016]

[0024] Numerical values ​​in the specification and claims of this application should be understood to encompass numerical values ​​that are the same when rounded to the same number of significant figures and that differ from the stated value within the experimental error of conventional measuring techniques of the type described in this application to determine those values.

[0017]

[0025] All ranges disclosed herein are inclusive of the stated endpoints and are independently combinable (e.g., the range "2 grams to 10 grams" includes the endpoints of 2 grams or 10 grams, and includes all intermediate values).

[0018]

[0026] The term "about" can be used to include any numerical value that can be varied without changing the basic function of the value. When used in conjunction with a range, "about" also discloses the range defined by the absolute values ​​of the two endpoints, for example, "about 2 to about 4" also discloses the range "2 to 4." The term "about" can refer to plus or minus 10% of the indicated number.

[0019]

[0027] The present disclosure relates to materials having a certain average particle size. The average particle size is defined as the diameter of particles that make up a cumulative percentage (by volume) of 50% of the total number of particles. In other words, 50% of the particles have a diameter greater than the average particle size, and 50% of the particles have a diameter less than the average particle size. The particle size distribution is Gaussian, with the upper and lower quartiles at 25% and 75% of the listed average particle size, and all particles being less than 150% of the listed average particle size.

[0020]

[0028] This disclosure may refer to temperatures for certain process steps. In this disclosure, temperatures typically refer to the temperature reached by the material being referred to, not the temperature set on a heat source (e.g., furnace, oven). The term "room temperature" refers to a range of 68°F (20°C) to 77°F (25°C).

[0021]

[0029] The term "bar" refers to a piece of material with a rectangular cross-section having a thickness greater than 0.48 mm. The term "plate" refers to a piece of material with a rectangular cross-section having a thickness greater than 4.78 mm. The term "strip" refers to a piece of material with a rectangular cross-section having a thickness of 4.78 mm or less. The term "slab" refers to a piece of material with a rectangular cross-section and may be used synonymously with the word "input" to refer to a starting piece of material that is processed into a coilable strip by the process of the present disclosure.

[0022]

[0030] The term "coil" refers to a length of material wound into a coil, which may be referred to as a single turn of material.

[0031] Rolling, as used herein, is a metal forming process in which the thickness of a stock input material is reduced by passing the stock input material through one or more pairs of rollers.

[0023]

[0032] Metal matrix composite (MMC) materials are typically provided as discrete strips or plates for final product processing. This is primarily due to the limited ductility of MMC materials. As a result, final products must typically be produced using batch processing methods, limiting the cost-effectiveness of MMC materials. It would be desirable to be able to process large quantities of material using automated coil-to-coil processing equipment. Therefore, it would be advantageous to produce a coiled form of MMC material.

[0024]

[0033] Cold working of MMC materials results in cracks. The cracks are due to the relatively low ductility of MMC materials at room temperature. The disclosed process avoids cracks, thus making it possible to produce coiled MMC strip. Coils of MMC strip are useful for high-volume coil-to-coil applications. This also allows for cost-effective storage / transportation of the material as well as the production of articles therefrom.

[0025]

[0034] Metal matrix composites are composite materials that include a metal matrix and reinforcing particles dispersed within the metal matrix. The metal matrix phase is typically continuous, while the reinforcing particles form a dispersed phase within the metal matrix phase.

[0026]

[0035] In the MMCs of the present disclosure, the matrix phase is formed from aluminum or an aluminum alloy. The reinforcing particles are ceramic materials selected from carbides, oxides, silicides, borides, and nitrides. Specific reinforcing particles include silicon carbide, titanium carbide, boron carbide, silicon nitride, titanium nitride, and zirconium oxide. In certain embodiments, silicon carbide is used.

[0027]

[0036] Reinforcement particles are 0.3 micrometers Ru~ 5 micrometer range, e.g., about 3 micrometerThe average particle size (D50) is defined as the particle diameter that reaches a cumulative percentage of 50 volume percent (vol%) of the total volume of particles. In other words, 50 vol% of the particles have a diameter greater than the average particle size, and 50 vol% of the particles have a diameter smaller than the average particle size.

[0028]

[0037] The MMC can include from about 10 vol% to about 50 vol%, such as from about 15 vol% to about 30 vol%, and from about 30 vol% to about 50 vol% of the reinforcing particles.

[0038] The aluminum alloy used in the MMC can be a 2000 series aluminum alloy (i.e., an aluminum alloy containing copper), a 6000 series aluminum alloy (i.e., an aluminum alloy containing magnesium and silicon), or a 7000 series aluminum alloy (i.e., an aluminum alloy containing zinc). Non-limiting examples of suitable aluminum alloys include 2009, 2124, 2090, 2099, 6061, and 6082.

[0029]

[0039] In some embodiments, the aluminum alloy comprises about 91.2 wt% to about 94.7 wt% aluminum, about 3.8 wt% to about 4.9 wt% copper, about 1.2 wt% to about 1.8 wt% magnesium, and about 0.3 wt% to about 0.9 wt% manganese.

[0030]

[0040] In another embodiment, the aluminum alloy comprises about 95.8 wt% to about 98.6 wt% aluminum, about 0.8 wt% to about 1.2 wt% magnesium, and about 0.4 wt% to about 0.8 wt% silicon.

[0031]

[0041] In some specific embodiments, the MMC comprises a 6061 series or 2124 series aluminum alloy reinforced with about 10 vol% to about 50 vol% silicon carbide particles, such as about 15 vol% to about 30 vol% and about 30 vol% to about 50 vol% silicon carbide particles.

[0032]

[0042] In a more specific embodiment, the MMC material can be made of 6061 aluminum alloy reinforced with 40 vol% silicon carbide particles. Physical properties of 6061 aluminum alloy reinforced with 40 vol% silicon carbide particles include the following:

[0033] [Table 1]

[0034]

[0043] In another specific embodiment, the MMC material can be made of 6061 aluminum alloy reinforced with 20 vol% silicon carbide particles. Physical properties of 6061 aluminum alloy reinforced with 20 vol% silicon carbide particles include the following:

[0035] [Table 2]

[0036]

[0044] In an additional embodiment, the MMC material can be made of 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles. Physical properties of 2124 aluminum alloy reinforced with 25 vol% silicon carbide particles include the following:

[0037] [Table 3]

[0038]

[0045] In a particular embodiment, the MMC material can be made from 2124 aluminum alloy reinforced with 17 vol% silicon carbide particles. Physical properties of 2124 aluminum alloy reinforced with 17 vol% silicon carbide particles include the following:

[0039] [Table 4]

[0040]

[0046] In other embodiments, the MMC material can be made from a 6063, 6082, 2009, or 2618 series aluminum alloy reinforced with about 10 vol% to about 50 vol% silicon carbide particles, e.g., about 15 vol% to about 30 vol%, or about 30 vol% to about 50 vol% silicon carbide particles.

[0041]

[0047] In some specific embodiments, the MMC material can be made of 2009 series aluminum alloys reinforced with 15 vol% silicon carbide particles. Physical properties of 2009 series aluminum alloys reinforced with 15 vol% silicon carbide particles include the following:

[0042] [Table 5]

[0043]

[0048] Generally, input MMC materials can be manufactured by any suitable method, such as powder metal production (e.g., but not limited to, powder metallurgy and high-energy mixing processes described above). To make the MMC materials of the present disclosure, an aluminum alloy is mixed with reinforcing particles to form a mixture. This mixture is consolidated, pressed, and extruded or hot rolled. This process produces a rectangular product, or slab, which is used as input material in the process of the present disclosure to make coiled MMC strip.

[0044]

[0049] For example, metal powder and ceramic particles can be mixed using high-energy techniques to distribute the ceramic reinforcing particles in the metal matrix. Suitable techniques for this mixing include ball milling, mechanical attritors, teamer mills, rotary mills, and other methods that provide high-energy mixing for the powder components. Mechanical alloying should be completed in air to avoid excessive oxidation of the powder. For example, an inert atmosphere can be provided using nitrogen or argon gas. Process parameters should be selected to achieve uniform distribution of the ceramic particles in the metal matrix.

[0045]

[0050] The powder from the high energy mixing stage can be degassed to remove any remaining moisture from the powder surface. This can be completed at 37°C to 500°C (100°F to 930°F).

[0046]

[0051] A hot pressing step may also be performed to increase the density of the reinforced composite structure. The hot pressing step may be performed at temperatures ranging from about 750°F (400°C) to about 1112°F (600°C), such as from about 795°F (425°C) to about 1020°F (550°C), and up to about 930°F (500°C). Hot pressing may involve the use of hot die pressing, hot isostatic pressing, or hot extrusion, typically at pressures of 30 to 150 MPa.

[0047]

[0052] The mixture is consolidated by hot isostatic pressing (HIP). In the HIP process, the powder is exposed to both elevated temperatures and high gas pressures in a high-pressure containment vessel, causing the powder to compact into a solid. The isostatic pressure is omnidirectional. The HIP process eliminates voids and pores. Hot isostatic pressing can be performed at temperatures between 660°F (350°C) and 1110°F (600°C) and pressures between 30 and 150 MPa for a period of time sufficient to bring the metal parts to the required temperature, typically 1 to 8 hours. Hot isostatic pressing can be performed in commercially available aluminum alloy, steel, or nickel HIP systems.

[0048]

[0053] The present disclosure relates to a method or process for converting a rectangular-shaped input material of MMC material into a coiled strip. Generally, the input material can have any thickness, e.g., a plate or strip. The input material can have any length, e.g., from a few feet to hundreds of feet. The processing method processes the MMC material at a combination of elevated and room temperatures to produce a strip of MMC material that can be wound into a coil. The methods disclosed herein use a combination of hot, warm, and cold working conditions to economically produce a coiled strip product.

[0049]

[0054] Generally, MMCs, such as the Al-SiC MMC disclosed above, exhibit limited ductility at room temperature. In other words, MMC materials have a limited ability to deform under pressure or compressive stresses, such as those imposed on input materials during rolling. Processing these materials by conventional methods to produce coiled strip results in cracking of the material. This significantly limits the ability to economically produce thin-gauge MMC strip. The cracking occurs due to the relatively low ductility of the MMC material at room temperature as well as the accumulation of cold work in the material.

[0050]

[0055] The ductility of MMC materials can be improved by increasing the temperature of the material during the rolling process of the present disclosure. As the temperature increases, several things happen to the material. First, the strength of the material decreases, allowing for a larger reduction in the material per given load during the rolling process. Second, the ductility of the aluminum matrix of the MMC material increases with temperature. At temperatures on the order of about 350°F (175°C) to about 600°F (315°C), the aluminum alloy microstructure within the Al-SiC MMC material recovers from the deformation induced by rolling. This allows for a much larger total deformation to be achieved than would be possible at lower temperatures.

[0051]

[0056] 1 is a flow chart illustrating process steps in an exemplary embodiment of a process 100 for fabricating coiled strip from rectangular-shaped MMC input material. In a first step 102, a rectangular-shaped slab of MMC material is provided as input material to a rolling apparatus, such as a rolling mill. The input material may be, for example, a strip or plate, and may have a relatively large thickness.

[0052]

[0057] In some embodiments, the input material is continuously fed, for example, via a continuous casting process. In these continuous processes, molten material solidifies into a rectangular input material shape for subsequent rolling in a rolling mill. In other embodiments, the input material may include discrete pieces of rectangular input material suitable for rolling in a batch process.

[0053]

[0058] The MMC input material undergoes a first hot working step 104. Hot working is a metal forming process in which the alloy is passed through rollers, dies, or forged, generally at temperatures above the recrystallization temperature of the alloy, to reduce the cross section of the alloy to produce the desired shape and dimensions. This generally reduces the directionality of mechanical properties and creates a new equiaxed microstructure. The amount of hot working performed is expressed as % reduction in thickness, or %FIW. Hot working is typically performed by hot rolling.

[0054]

[0059] Rolling is a metal forming process in which an input material is passed through one or more pairs of rollers to reduce and uniform the thickness of the input material. Hot rolling involves raising the temperature of the metal above its recrystallization temperature. The hot rolling process is carried out at a temperature of about 900°F (480°C) to about 1050°F (565°C), i.e., the input material is heated to this temperature before passing through the rolling mill. The input material is relatively thick and therefore maintains the required temperature during the hot rolling process. In some embodiments, the input material is already in a heated state, for example, taken directly from a continuous casting process. In other embodiments, the MMC input material is heated to the desired hot working temperature from a temperature below the desired hot working temperature.

[0055]

[0060] It is contemplated that the input material will not be canned while it is being heated or hot-worked. Canning refers to sandwiching the input material between two sheets of metal and then welding / sealing the two sheets to enclose the input material. Canning isolates the input material from the surrounding atmosphere or environment, which may be potentially oxygen-rich and contain contaminants. Therefore, canning the material while it is being heated reduces corrosion and oxidation of the material, as oxidation occurs more rapidly at molten metal temperatures. Canning is generally only useful when the input material is less than about 4 feet in length, which does not occur in contemplated commercial manufacturing processes.

[0056]

[0061] The thickness reduction (% HW) of the input material in the hot working process 104 can vary. Generally, the MMCs of the present disclosure can be hot rolled at thickness reductions of up to 30% per pass. In some embodiments, the thickness reduction per pass is about 5% to about 30%. In other embodiments, the thickness reduction per pass is about 10% to about 30%. In some embodiments, the hot rolling thickness reduction per pass can be about 10% to about 25%. The input material can go through more than one rolling pass. In some embodiments, the input material can go through the mill rolls 2, 3, 4, 5, 6, 7, 8, 9, or 10 times.

[0057]

[0062] The maximum total reduction (% HW) during the hot working process, i.e., after all hot rolling passes are completed, is about 75% of the input material thickness of the MMC material, although reductions greater than 75% are acceptable. If the workpiece becomes too thin, it will lose heat too quickly and hot working will not occur. In some embodiments, intermediate reheating of the input material between rolling passes is not required. In other embodiments, the material may be reheated between rolling passes.

[0058]

[0063] After the hot working step, the hot worked MMC material undergoes a warm working process 106, which is typically accomplished by warm rolling. The warm rolling step occurs while the hot worked MMC material is still at an elevated temperature. Desirably, the MMC material is at a temperature of about 350°F to about 600°F (about 175°C to about 315°C). In some embodiments, the rollers used for warm rolling are also heated to this temperature. In other words, the rollers are heated to conduct heat into the MMC material. Generally, MMCs are good thermal conductors, and the MMC material is thin enough after hot working that heat can penetrate the entire thickness of the MMC material.

[0059]

[0064] In some embodiments, at least one roller of the rolling mill used in the warm working step is heated. The roller may be heated to match the temperature range preferred for warm rolling. The roller may be heated by various methods known in the art, for example, by inserting a resistive heating element into the roller.

[0060]

[0065] The thickness reduction (%WW) of the MMC material in the warm working process 106 can be up to 65% per rolling pass. In other embodiments, the reduction per pass is between about 5% and about 65%. In some embodiments, the warm working reduction can be between about 10% and about 30%. In some embodiments, the warm working reduction can be between about 10% and about 25%. In some embodiments, the warm working process includes multiple passes through a rolling mill. In some embodiments, the input MMC material can be passed through the rolling mill 2, 3, 4, 5, 6, 7, 8, 9, or 10 times.

[0061]

[0066] The total thickness reduction (reduction) of the warm working steps, i.e., the total reduction after all warm rolling passes are completed, is at least 75% of the starting thickness (i.e., the thickness of the MMC material after hot working has occurred). In some embodiments, the total thickness reduction of the warm working steps is about 90% of the starting thickness of the MMC material after hot working has occurred.

[0062]

[0067] The warm rolling process 106 is advantageous because it eliminates or at least significantly reduces the presence of edge cracks in the MMC material. The warm rolling process also allows for a greater reduction in thickness of the MMC material per pass of the rolling mill compared to cold working. The relatively low rolling temperatures compared to hot rolling temperatures limit oxidation of the material, since the material is more susceptible to rapid oxidation at hot rolling temperatures.

[0063]

[0068] In some embodiments, after the warm working process 106, the MMC material undergoes an optional cold working process 108. That is, the material from the warm working process is allowed to cool before being fed to a processing mill. Cold working is a process in which the shape or size of a metal is mechanically altered by plastic deformation. This can be done by rolling, deep drawing, pressing, spinning, extruding, or heading the metal or alloy. When a metal is plastically deformed, atomic rearrangements occur within the material. Specifically, dislocations occur across or within the grains of the metal. Dislocations overlap each other, increasing the dislocation density within the material. The increased overlapping dislocations make it more difficult for additional dislocations to move. This increases the hardness and tensile strength of the resulting alloy, but generally reduces the alloy's ductility and impact properties. Cold working also improves the surface finish of the alloy. Mechanical cold working is generally performed below the recrystallization point of the alloy, usually at room temperature. The percent cold work (% CW), or degree of deformation, can be determined by measuring the change in cross-sectional area of ​​the alloy before and after cold working.

[0064]

[0069] The cold working process 108 is carried out at about room temperature. The MMC material itself should be at room temperature. Due to the limited ductility of the MMC material, the total reduction in thickness (% CW) of the MMC material is limited to about 10% or less. In some embodiments, the cold working process includes multiple passes through a rolling mill. In some embodiments, the MMC material may be passed through the rolling mill 2, 3, 4, 5, 6, 7, 8, 9, or 10 times.

[0065]

[0070] Desirably, after these steps, the resulting MMC strip has a thickness of about 0.04 millimeters (mm) to about 1.25 mm.

[0071] In some embodiments, process 100 further includes a winding step 110. That is, with reference to FIG. 2, the material can be wound around itself to create a larger roll or coil 200 of material. In some embodiments, the material is wound around a core 210. In some embodiments, the coil form 200 has an inner diameter ID of about 16 inches to about 20 inches. In some embodiments, the coil form has an outer diameter OD of about 60 inches to about 72 inches. The core 210 also provides a means by which the material can be stored and transported.

[0066]

[0072] The resulting MMC coiled strip material can be used for mass production of MMC materials. The MMC materials can be rewound and converted into useful articles for applications such as space, defense, aerospace, automotive, OEM, consumer goods, appliances, and transportation applications. For example, the rewound MMC strip can be die-cut, cut, etc. to form articles. Articles can include outlet guide vanes, hydraulic / fuel blocks, wheels, fixed-wing structures / skins, helicopter parts, pistons, piston pins, cylinder liners, brake calipers, connecting rods, push rods, chassis components, optical sensors, and satellite structures.

[0067]

[0073] The following examples are provided to illustrate the compositions, articles, and methods of the present disclosure. The examples are merely illustrative and are not intended to limit the disclosure to the materials, conditions, or process parameters described therein. [Example]

[0068]

[0074] Comparative Example 1

[0075] MMC pieces made of 6061 aluminum alloy reinforced with 20 vol% SiC particles were extruded to a thickness of 3.55 mm (0.140 in.) and cut to a width of 12.065 cm (4.75 in.). These pieces were cold rolled at 10% CW per pass. Edge cracking occurred, as can be seen in Figures 3A and 3B.

[0069]

[0076] Example 1

[0077] MMC strips made from 6061 aluminum alloy reinforced with 20 vol% SiC particles were extruded to a thickness of 3.55 mm (0.140 in) and cut to a width of 12.065 cm (4.75 in). These strips were warm rolled at temperatures between 450°F and 550°F (232°C and 287°C) to a thickness of 0.46 mm (0.018 in), or 87% thickness %WW and 12.065 cm (4.75 in) width. As shown in Figure 4, no cracks were present in the material. The material was easily coiled.

[0070]

[0078] Example 2

[0079] A piece of MMC made from 6061 aluminum alloy reinforced with 20 vol% SiC particles was extruded to a thickness of 3.55 mm (0.140 in) and a width of 11.43 cm (4.5 in). The ends were left as extruded.

[0071]

[0080] The samples were preheated using a Grieve furnace. The furnace was set to 700°F (370°C) and the samples were held in the furnace for 30 minutes. The MMC samples were warm-rolled using a Fenn rolling mill. The rollers were preheated to approximately 600°F (315°C) before rolling. The samples were transferred from the furnace to the rolling mill using thermal gloves. The MMC samples were placed on the entry table of the rolling mill, and the rolling sequence was immediately engaged. The temperature was measured at the start of the rolling process by contacting a pyrometer with the tail of the material. After exiting the rolling mill, the samples were quickly returned to the entry side of the rolling mill. For the first sample, the temperature was allowed to drop below 400°F (204°C) after seven passes were completed. Data for each pass of the first sample (22.86 cm (9 inches) of input material length) are listed in Table 1 below.

[0072]

[0081] Table 2 shows data for a second sample with a starting thickness of 3.55 mm (0.140 inch) and an input material length of 22.86 cm (9 inches). Table 3 shows data for a third sample with a starting thickness of 3.55 mm (0.140 inch) and an input material length of 45.72 cm (18 inches). Table 4 shows data for a fourth sample with a starting thickness of 3.55 mm (0.140 inch) and an input material length of 91.44 cm (36 inches). Table 5 shows data for a fifth sample with a starting thickness of 3.55 mm (0.140 inch) and an input material length of 121.92 cm (48 inches).

[0073] [Table 6]

[0074] [Table 7]

[0075] [Table 8]

[0076] [Table 9]

[0077] [Table 10]

[0078]

[0082] Example 3

[0083] MMC strips of 6061 aluminum alloy reinforced with 20 vol% SiC particles were prepared as in Example 2, but with a starting thickness of 1.45 mm (0.057 in) and a starting length of 52.07 cm (20.5 in). The ends were left extruded. The samples were then rolled using warm rollers. The process was the same as in Example 2. The results for each pass are listed in Table 6 below. The final strip was 164.846 cm (64.9 in) in length.

[0079] [Table 11]

[0080]

[0084] FIG. 5 is a photograph of the coiled MMC strip exiting the rolling mill used for warm rolling.

[0085] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, changes, or improvements thereon may be made by those skilled in the art, which are also intended to be encompassed by the following claims or their equivalents. Specific embodiments of the present invention are as follows. [Aspect 1] 1. A method of manufacturing a strip of metal matrix composite (MMC) material, comprising: hot working the rectangular charge of MMC material to produce a hot rolled MMC material; and warm working the hot rolled MMC material to obtain a strip of the MMC material; The method comprising: [Aspect 2] 10. The method of embodiment 1, further comprising winding the strip of MMC material into a coil. [Aspect 3] 3. The method of claim 1 or 2, wherein the hot working is performed at a temperature of from about 900°F (482°C) to about 1050°F (565°C). [Aspect 4] 4. The method of any one of aspects 1 to 3, wherein the hot working is to a total %FIW of at least 75%. [Aspect 5] 5. The method of any one of the preceding aspects, wherein the hot working is done in multiple hot passes, each hot pass resulting in a %FIW of 20% or less. [Aspect 6] 6. The method of any one of aspects 1 to 5, wherein the warm working is performed at a temperature of about 350°F to about 600°F (about 177°C to about 315°C). [Aspect 7] 7. The method of any one of aspects 1 to 6, wherein the warm-working is performed using heated rollers. [Aspect 8] 8. The method of any one of the preceding aspects, wherein the warm working is to a total %WW of at least 75%. [Aspect 9] 9. The method of any one of the preceding aspects, wherein the warm working is done in multiple warm passes, each warm pass resulting in a %WW of 65% or less. [Aspect 10] 10. The method of any one of the preceding embodiments, further comprising cold working the strip of MMC material after said warm working. [Aspect 11] 11. The method of embodiment 10, wherein said cold working is to a total % CW of about 10% or less. [Aspect 12] 12. The method of any one of the preceding aspects, wherein the MMC material comprises an aluminum alloy and ceramic particles dispersed within the aluminum alloy. [Aspect 13] 13. The method of embodiment 12, wherein the ceramic particles comprise at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides. [Aspect 14] 14. The method of claim 12 or 13, wherein the MMC material comprises about 15 vol% to about 50 vol% ceramic particles. [Aspect 15] 15. The method of any one of aspects 12 to 14, wherein the ceramic particles have an average particle size of about 0.3 pm to about 5 pm. [Aspect 16] 16. A coiled strip of metal matrix composite (MMC) material made according to the method of any one of embodiments 1 to 15. [Aspect 17] An article made from a non-coiled strip of metal matrix composite (MMC) material.

Claims

1. 1. A method for producing a strip of aluminum-silicon carbide metal matrix composite (MMC) material, comprising: hot working said aluminum-silicon carbide MMC material input having a rectangular cross section to produce a hot rolled MMC material; warm working the hot rolled MMC material to obtain a strip of the MMC material; and cold working the strip of MMC material after said warm working; Including, The process wherein the warm working is carried out at a temperature of 350°F to 600°F (177°C to 315°C).

2. The method of claim 1 further comprising winding the strip of MMC material into a coil.

3. The method of claim 1 or 2, wherein the hot working is carried out at a temperature of from 900°F (482°C) to 1050°F (565°C).

4. 4. The method of any one of claims 1 to 3, wherein the hot working is performed to a total thickness reduction (%FIW) of at least 75%.

5. 5. The method of any one of claims 1 to 4, wherein the hot working is performed in multiple hot passes, each hot pass resulting in a thickness reduction (%FIW) of 20% or less.

6. 6. The method of any one of claims 1 to 5, wherein the warm working is performed using heated rollers.

7. 7. The method of any one of claims 1 to 6, wherein the warm working is performed to a total thickness reduction (%WW) of at least 75%.

8. 8. The method of any one of claims 1 to 7, wherein the warm working is performed in multiple warm passes, each warm pass resulting in a thickness reduction (%WW) of 65% or less.

9. 9. The method of any one of claims 1 to 8, wherein the cold working is performed to a total percent cold work (% CW) of 10% or less.

10. The method of any one of claims 1 to 9, wherein the MMC material comprises an aluminum alloy and ceramic particles dispersed within the aluminum alloy.

11. The method of claim 10, wherein the ceramic particles comprise at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides.

12. The method of claim 10 or 11, wherein the MMC material comprises 15 vol% to 50 vol% ceramic particles.

13. 13. The method of any one of claims 10 to 12, wherein the ceramic particles have an average particle size of 0.3 micrometers to 5 micrometers.

Images