JPH04341537A - Aluminum alloy having high strength and wear resistance and excellent in cold forgeability - Google Patents

Abstract

PURPOSE:To obtain the alloy by incorporating Mn and Cr and specifying a composition in an alloy where hard grains of SiC, etc., are dispersed into an Al-Cu-Mg-Si series. CONSTITUTION:This Al alloy has a composition consisting of, by weight, 2.5-5.5% Cu, 0.3-2.5% Mg, 0.1-0.19% Si, 0.3-1.0% Mn and/or Cr, and the balance Al and further containing, if necessary, 0.02-0.7% Ti and/or Zr. The Al alloy can be prepared by dispersing one or more kinds among ceramic grains of Si, Si3N4, etc., metal grains of ferromolybdenum, Co-Cr-W-C alloy, Co-Cr-Mo-Si alloy, etc., and grains harder than the matrix alloy, e.g., intermetallic compound, such as TiAl and FeAl, by 0.2-5vol.% into the Al alloy matrix. This Al alloy combines superior strength and wear resistance with excellent cold forgeability and can be suitably used for producing engine parts, such as valve lifter and valve spring retainer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention improves the wear resistance of an excellent high-strength aluminum alloy, and is applicable to valve lifters, valve spring retainers, oil pump gears, sprockets, pulleys, and other engine parts. This invention relates to a high-strength, wear-resistant aluminum alloy with excellent forgeability.

0002

2. Description of the Related Art Recently, engines have been manufactured using aluminum alloys instead of conventional steel materials to reduce weight and save energy. However, valve lifters, valve spring retainers, pulleys, and other engine parts in particular require high-temperature strength and wear resistance.
Until now, iron-based materials have been mainly used.

[0003] When Al alloys are used to reduce the weight of these parts, ordinary Al alloys lack wear resistance. Therefore, in order to compensate for the lack of wear resistance, materials have been developed that are composites of ceramic particles in Al (for example, JP-A No. 6
4-56844). In order to mass produce these parts, it is desirable to form them by cold forging, but cold forging is difficult with the above materials.

0004

[Problem to be Solved by the Invention] In order to solve this problem first, an alloy made of Al--Cu--Mg--Si with SiC and other hard particles dispersed therein has been developed. (Patent Application No. 2-96487) This alloy has excellent cold forgeability, but in order to mass produce parts with complex shapes, an alloy with even better cold forgeability is required. has been done.

[0005] In view of these points, the present invention aims to provide an aluminum alloy that has both high strength and wear resistance, and also has sufficient cold forgeability.

[0006]

[Means for Solving the Problems] The present invention provides Cu: 2.5
~5.5%, Mg: 0.3~2.5%, Si: 0.1~
0.19%, and one or both of Mn and Cr: 0.19%.
3 to 1.0%, or further contains Ti and Z.
SiC, Si3N4, ZrO2,
Ceramic particles such as Al2O3, ZrSiO4, mullite or metal particles such as ferromolybdenum, Co-Cr-W-C alloy, Co-Cr-Mo-Si alloy, tungsten or intermetallic compounds such as TiAl, FeAl, Ni3Al. This is a high-strength, wear-resistant aluminum alloy with excellent cold forgeability, which is made by dispersing 0.2 to 5 vol% of one or more types of particles harder than the matrix alloy.

The reasons for limiting the alloy components and hard particles in the above are as follows.

[0008] Cu: Improves strength at room temperature and high temperature. 2.
If it is less than 5%, the effect will be small, and if it exceeds 5.5%, cold forgeability will deteriorate.

[0009] Mg: Coexists with Cu and ages hardens to increase strength at room temperature and high temperature. If it is less than 0.3%, the effect is not sufficient, and if it exceeds 2.5%, cold forgeability deteriorates.

[0010]Si: By adding Si, Al-Cu-Mg
The system precipitated intermediate phase (S') is formed finely, and the amount of age hardening increases. Furthermore, if Mn or Cr (described later) coexists, an Al-Mn-Si precipitate phase or Al-Cr-S
An i-based precipitate phase is generated, which enhances the pinning effect of dislocations and becomes a subgrain structure or a fine recrystallized structure. If it is less than 0.1%, no effect will be observed, and if it exceeds 0.19%, some Si will precipitate on the grain boundaries, reducing cold forgeability.

Mn, Cr: As mentioned above, they coexist with Si and the recrystallized structure becomes fine. As a result, the room temperature and high temperature strength of the T4 or T6 treated material is improved, and at the same time, the ductility and toughness are also improved. The effect of improving ductility and toughness appears most strongly when the content is 0.5 to 0.6%, and the effect is insufficient when the content is less than 0.3% or more than 1.0%. Furthermore, when the content is less than 0.3%, no improvement in strength is observed.

Ti, Zr: refines crystal grains during solidification, suppresses recrystallization that occurs during solution treatment, creates a fibrous structure or a structure with fine recrystallization,
Improve strength. If the total amount is less than 0.02%, the effect will be small, and if it exceeds 0.7%, the effect will be saturated.

Hard particles: SiC, Si3N4, ZrO2
, Al2O3, ZrSiO4, ceramic particles such as mullite, ferromolybdenum, Co-Cr-W-C alloy, C
By adding hard particles such as o-Cr-Mo-Si alloys, metal particles such as tungsten, or intermetallic compounds such as TiAl, FeAl, Ni3Al, the wear resistance is greatly improved. If it is less than 0.2 vol%, wear resistance will not be sufficient, and if it exceeds 5 vol%, cold forgeability and machinability will deteriorate.

[0014]

EXAMPLE An aluminum alloy containing hard particles having the components shown in Table 1 was produced. The manufacturing method is as follows.

After producing various Al alloy powders by air atomization, they were classified to 149 μm or less, and hard particles of a predetermined particle size and amount were added thereto and mixed using a ball mill. After charging this mixed powder into an aluminum can with an outer diameter of 2.5 inches, vacuum degassing treatment was performed at 480°C for 1 hour to remove the air inside the can and moisture adsorbed on the powder surface. This was made into a billet for extrusion. This was extruded at 400°C to a diameter of 18 mm (extrusion ratio 15). Then, in order to evaluate cold forgeability, a softening treatment (holding at 300° C. for 5 hours → air cooling) was performed, and an upsetting test was conducted to measure the limit upsetting rate. In addition, T6 treatment (495°C x 1h holding → water quenching → 1
A tensile test and a pin-disk abrasion test were conducted. The results are also listed in Table 1. Here, the amount of wear is 50 kgf/cm2 (4.9 MP
This is the reduction in the length of the pin under a) friction is performed for 1 hour at a surface pressure of 0.5 m/sec and a speed of 0.5 m/sec.

[0016]

[Table 1]

[0017] As is clear from Table 1 above, the present invention alloy No. Nos. 1 to 14 exhibit high strength, elongation, and limit upsetting rate, and furthermore, pin wear is small. In contrast, comparative alloy No. Since No. 15 does not contain hard particles, the amount of pin wear is large. No. No. 16 does not have sufficient strength due to a small amount of Cu. No. 17 has a low marginal upsetting rate because it contains a lot of Cu. No. 18 does not have sufficient strength due to low Mg content, and N
o. No. 19 has a low marginal upsetting rate due to its high Mg content. No.
No. 20 has a low marginal upsetting rate because it has a large amount of Si.

[0018]

[Effects of the Invention] According to the present invention, an aluminum alloy having excellent strength and wear resistance as well as excellent cold forgeability can be obtained. Therefore, the alloy of the present invention can be used in valve lifters, valve spring retainers, etc.
This material is suitable for engine parts and can replace conventional steel products.

Claims (2)

[Claims] [Claim 1] Cu: 2.5 to 5.5% (weight %: same below), Mg: 0.3 to 2.5%, Si: 0.1 to 0
．． 19% and one or two of Mn and Cr: 0.3
SiC,
Ceramic particles such as Si3N4, ZrO2, Al2O3, ZrSiO4, mullite or metal particles such as ferromolybdenum, Co-Cr-W-C alloy, Co-Cr-Mo-Si alloy, tungsten or TiAl, F
One or more types of particles harder than the matrix alloy such as intermetallic compounds such as eAl and Ni3Al are mixed with 0.
A high-strength, wear-resistant aluminum alloy with excellent cold forgeability made by dispersing 2 to 5 vol%. [Claim 2] Cu: 2.5 to 5.5%, Mg: 0.
3 to 2.5%, Si: 0.1 to 0.19%, and further one or two of Mn and Cr: 0.3 to 1.0%, one or two of Ti and Zr: 0. SiC, Si3N4, ZrO2, Al2
O3, ZrSiO4, ceramic particles such as mullite or ferromolybdenum, Co-Cr-W-C alloy, C
Dispersion of 0.2 to 5 vol% of one or more particles harder than the matrix alloy, such as o-Cr-Mo-Si alloy, metal particles such as tungsten, or intermetallic compounds such as TiAl, FeAl, and Ni3Al. A high-strength, wear-resistant aluminum alloy with excellent cold forging properties.