Lead-free brass alloy and use thereof

Abstract

To provide a lead-free brass alloy which has good machinability, emergency operation properties, oil compatibility and the like, and is suitable for producing parts for hydraulic pumps and hydraulic components.SOLUTION: A lead-free brass alloy contains 57.0 to 60.0% of Cu, 1.0 to 2.0% of Al, 1.5 to 2.5% of Mn, 0.1 to 1.0% of Fe, at most 0.5% of Ni, at most 0.5% of Sn, 0.5 to 2.0% of Si, and less than 0.1% of Pb, with the balance consisting of Zn and unavoidable impurities, where the copper equivalent (CuEq) is in the range from 52.0 to 58.0%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a lead-free brass alloy and its use.

Background Art

[0002] US10,287,653B2 describes a lead-free brass alloy having the composition described in claim 1 of that patent. This known brass alloy has a zinc equivalent of 51% to about 58%. The proposed brass alloy is particularly suitable for the manufacture of bearings for turbochargers.

[0003] The industry requires a lead-free brass alloy that is particularly suitable for manufacturing parts of hydraulic pumps and hydraulic components.

Summary of the Invention

[0004] The object of the present invention is to identify a lead-free brass alloy that is remarkable in terms of good machinability, emergency operation characteristics, oil compatibility, etc. This brass alloy is particularly suitable for manufacturing parts of hydraulic pumps and hydraulic components.

[0005] This object is achieved by the features of claims 1 and 7. Preferred embodiments are apparent from the features of the dependent claims.

Mode for Carrying Out the Invention

[0006] Proposed according to the present invention is a lead-free brass alloy containing 57.0 - 60.0% Cu, 1.0 - 2.0% Al, 1.5 - 2.5% Mn, 0.1 - 1.0% Fe, 0.5% or less Ni, 0.5% or less Sn, 0.5 - 2.0% Si, and less than 0.1% Pb, with the balance being Zn and unavoidable impurities, and having a copper equivalent (CuEq) of 52.0 - 58.0%.

[0007] The specified copper equivalent (CuEq) is calculated as follows. 1) Si freeIn the case where =Si·3.26-(Fe+Mn) < 0, CuEq=Cu / {[100-Fe-Mn+(|Si free The formula is |·0.7)-Al+(Al·6)-Si)] / 100}. 2) Si free In the case where =Si·3.26-(Fe+Mn) > 0, CuEq=Cu / {[100-Fe-Mn-Al+(Al 6)-Si+((Si free It is ( / 3.26)·10) / 100}. Cu:% Copper Fe:% Iron Al:% Aluminum Si: % silicon

[0008] For the purposes of this specification, [%] is understood to mean weight percent.

[0009] In the above calculation of copper equivalent (CuEq), two cases, number 1 and number 2, are distinguished. In case number 1, there is free silicon (Si) in the alloy. free It does not exist. In this case, silicon in the alloy is completely bonded with Fe and / or Mn. An intermetallic Fe-Mn-Si compound is formed.

[0010] In case number 2, free silicon (Si) is present in the alloy. free Free silicon (Si) exists in alloys. free This case requires distinguishing between the first and second cases because it causes a strong shift in the β phase direction in the phase diagram. In this case, the shift in the phase diagram towards the β phase is about 10 times stronger than in the case where silicon is completely bonded (see calculation above, case number 1).

[0011] Brass alloys with a copper equivalent (CuEq) of 52.0-58.0% have been shown to exhibit frictional properties comparable to conventional lead-containing alloys. Furthermore, the proposed lead-free brass alloy is noteworthy for its good machinability, emergency operation characteristics, and oil compatibility.

[0012] According to an advantageous embodiment, Si is included in an amount of 1.0% or less. In this way, a particularly suitable content of the β phase is achieved.

[0013] According to another embodiment, Sn is included in an amount of 0.2% or less, preferably 0.1% or less, more preferably less than 0.06%. Sn improves the relaxation resistance of the alloy.

[0014] The proposed lead-free brass alloy may contain nickel in an amount of 1.0% or less, preferably 0.5% or less. Further, Fe may be included in an amount of 0.5% or less, preferably 0.4% or less. Mn may be included in an amount of 2.1% or less. The aforementioned elements are added to form an intermetallic layer in the alloy. The intermetallic layer improves the wear resistance and ductility of the alloy.

[0015] Furthermore, according to the present invention, a specification of the lead-free brass alloy of the present invention for manufacturing parts of a hydraulic pump and hydraulic components is proposed. This part may be particularly selected from the following group: sliding block, distribution plate, retaining segment, and bearing bush.

[0016] The proposed brass alloy is particularly suitable for manufacturing parts of a hydraulic pump and hydraulic components because of its good friction characteristics.

[0017] According to an exemplary embodiment of the present invention, the alloy of the present invention has, for example, the following composition.

[0018] <�

Table 1

[0019] The alloy having the above composition exhibits the characteristics specified in the following table.

[0020]

Table 2

[0021] The excellent frictional properties of the alloy of the present invention make it particularly suitable for the manufacture of hydraulic pumps and hydraulic components, more specifically sliding blocks, distribution plates, retaining segments and bearing bushings.

Claims

1. The following elements: 57.0 - 60.0% Cu 1.0 - 2.0% Al 1.5 - 2.5% Mn 0.1 - 1.0% Fe 0.5% or less Ni 0.5% or less Sn 0.5 - 2.0% Si Less than 0.1% Pb A lead - free brass alloy containing the above and the balance being Zn and inevitable impurities, wherein the copper equivalent (CuEq) is 52.0 - 58.0%, said lead - free brass alloy.

2. The lead - free brass alloy according to Claim 1, containing Si in an amount of 1.0% or less.

3. The lead - free brass alloy according to Claim 1, containing Sn in an amount of 0.2% or less.

4. The lead - free brass alloy according to Claim 3, containing Sn in an amount of 0.1% or less.

5. The lead - free brass alloy according to Claim 3, containing Sn in an amount less than 0.06%.

6. The lead - free brass alloy according to Claim 1, containing Ni in an amount of 1.0% or less.

7. The lead - free brass alloy according to Claim 6, containing Ni in an amount of 0.5% or less.

8. The lead - free brass alloy according to Claim 1, containing Fe in an amount of 0.5% or less.

9. The lead - free brass alloy according to Claim 8, containing Fe in an amount of 0.4% or less.

10. The lead - free brass alloy according to Claim 1, containing Mn in an amount of 2.1% or less.

11. Use of the lead - free brass alloy according to any one of Claims 1 - 10 for manufacturing parts of hydraulic pumps and hydraulic components.

12. The use according to Claim 11, wherein said parts are selected from the following group: sliding blocks, distribution plates, retaining segments and bearing bushes.