JPS6214206B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a wear-resistant aluminum alloy used in, for example, VTR cylinder heads and other various mechanical parts that require wear resistance. Conventionally, as this type of wear-resistant aluminum alloy, Al-Si alloy is well known and generally widely used. This alloy is manufactured into the desired product by cutting its extrusion or casting, but conventional products generally have problems with machinability, especially when it comes to chip disposal. Automation of cutting processing is hindered due to poor performance.
Furthermore, there was a problem of poor productivity. This invention aims to solve such problems. For the above purpose, the present inventor conducted various studies on Al-Si alloys with the intention of improving them, and found that in the conventionally known alloys of the above-mentioned type,
Even if the amount of Si, which is the main hardening element, is significantly reduced, machinability and In particular, it has been found that chip disposal can be significantly improved. This invention was completed based on this knowledge, and it contains Si: 1.0 to 4.5%, Cu: 1.0 to 6.0%, Mg: 0.2 to 3.0%, and in addition, Pb, Sn, and Bi. Provided is an aluminum alloy characterized by containing two or more of 0.1 to 5.0% each, or further containing 3% or less of Ni, and the remainder substantially consisting of Al, if necessary. It is. In this specification, all "%" means "% by weight". The significance of the above-mentioned alloy additive elements and the reason for limiting their content are as follows. In other words, Si improves wear resistance and strength, and if it is less than 1.0%, it is ineffective, and if it exceeds 4.5%, it not only reduces the life of the cutting tool but also causes poor hot and cold workability. Become. particularly preferred
The range of Si content is approximately 2.5 to 3.5%. In addition, Cu and Mg are both added to increase strength, and Cu is less than 1.0% and
This effect is small when Mg is less than 0.2%, and on the contrary Cu
If Mg exceeds 6.0% or Mg exceeds 3.0%, coarse crystallized substances are formed and mechanical properties deteriorate. Particularly preferable contents thereof are approximately 2.0 to 4.0% for Cu and 0.5 to 1.0% for Mg. Pb, Sn, and Bi are all necessary to improve cutting properties such as chip disposal and cutting tool life, and it is necessary to contain at least two or more of them. If there is only one type of these or if the content of each is less than 0.1%, the above effects will not be obtained, and if it exceeds 5.0%, corrosion resistance and surface treatment properties will decrease. Therefore, especially 0.5-1.0% each
It is preferable that the content be within a certain range. Furthermore, Ni content in a range of 3% or less is effective in reducing the coefficient of thermal expansion and maintaining good dimensional accuracy, and a content of about 1.0% is particularly preferable. As is clear from the following examples, the aluminum alloy according to the present invention has relatively good wear resistance compared to comparative alloys in which one or more of the alloy compositions deviate from the range of limitations. It is possible to significantly improve the machinability evaluated in terms of chip disposability and cutting tool wear (tool life) while maintaining the same properties.In particular, the marked improvement in chip disposability makes it possible to automate the cutting process. This can contribute to improving the productivity of machine parts such as VTR cylinders made of wear-resistant Al alloys. Examples of this invention are shown below. Example

[Table] Each of the present invention alloy and comparative alloy shown in Table 1 above was cast into a 6-inch billet.
Homogenization treatment was performed at 500°C for 4 hours. then 460
Extruded into a round bar with a diameter of 30 mm at ℃, and heated at 500℃ x 2
The test material was subjected to solution treatment for 1 hour and aging treatment at 180°C for 7 hours. The wear resistance and machinability of each sample material were then examined. The results are shown in Table 2. The wear resistance test was conducted using an Okoshi type wear tester with a rotating disk, load: 2.1Kg, friction distance: 600m, friction speed: 0.96m/s, 2.1m/s,
The evaluation was made by measuring the specific wear amount of the sample material when rubbed under the test conditions of 4.4 m/s, mating material: FC-30 (JIS), test surface: Emery pepper No. 1200 finish. In addition, the machinability test was as follows: front rake angle: 0 degrees, side rake angle: 10 degrees, front relief angle: 7 degrees, side relief angle: 7
A high-speed hard cutting tool (SKH-4) with the following specifications: front cutting edge angle: 8 degrees, side edge angle: 0 degrees, nose radius: 0 degrees is used to improve chip control and cutting tool wear. Comprehensive evaluation was performed, and good results were given as ○, somewhat good results were given as △, and poor results were given as ×.

【table】

[Table] *(2)...Comprehensive evaluation of machinability - chip control and tool wear

Claims (1)

[Claims] 1 Contains: 1.0 to 4.5% of Si, 1.0 to 6.0% of Cu, 0.2 to 3.0% of Mg, and two or more of Pb, Sn, and Bi: 0.1 to 5.0% each. A wear-resistant aluminum alloy with excellent machinability, characterized in that it contains , and the remainder consists of Al and inevitable impurities. 2 Contains Si: 1.0 to 4.5%, Cu: 1.0 to 6.0%, Mg: 0.2 to 3.0%, and contains two or more of Pb, Sn, Bi: 0.1 to 5.0% each, and further contains A wear-resistant aluminum alloy with excellent machinability, characterized by containing 3% or less of Ni, with the remainder consisting of Al and unavoidable impurities.