JPS6126744A - Wear resistant aluminum alloy - Google Patents

Abstract

PURPOSE:To obtain a wear resistant Al alloy by adding specified amounts of Si, Cu, Mg, Ni, Ti, Ca and Na to Al. CONSTITUTION:The composition of an Al alloy is composed of, by weight, 12- 14% Si, 4-5.5% Cu, 0.5-1.5% Mg, 0.5-1.5% Ni, 0.1-0.25% Ti, <0.005% Ca, <0.001% Na and the balance Al with inevitable impurities. An Al alloy having superior wear resistance and undergoing hardly reduction in the machinability and shock resistance is obtd. by specifying the kinds and contents of chemical components as mentioned above.

Description

DETAILED DESCRIPTION OF THE INVENTION A8 OBJECTS OF THE INVENTION (11) INDUSTRIAL APPLICATION FIELD The present invention relates to a wear-resistant aluminum alloy suitable as a constituent material of sliding members for internal combustion engines.

(2) Prior Art Conventionally, the constituent materials for sliding members for internal combustion engines, such as pistons, are JIS ACBA material (Si 11-13% by weight), AC8B material C8t (8.5-10.5% by weight).
, ACBC material (Si 8.5-10°5% by weight) and other eutectic type aluminum alloys represented by Lowex, JIS ACQA material (Si 22-24 weight%), AC9B material (Si 18- Hypereutectic type high silicon aluminum alloys such as 20% by weight) are used.

(3) Problems to be solved by the invention However, in hypereutectic type high-silicon aluminum alloys, a large amount of hard primary Si is dispersed within the structure.
Although it has superior wear resistance compared to eutectic type aluminum alloys, it has a problem in that its machinability and impact resistance are reduced, which limits its use. In particular, when the piston is made of the high-silicon aluminum alloy,
Since primary crystal Si having a large particle size easily falls off, the dropped primary crystal Si becomes a cause of accelerating wear.

Therefore, in the constituent material of a sliding member such as a piston, it is necessary to uniformly disperse and crystallize an appropriate amount of primary crystal Si having an appropriate particle size.

In view of the above, the present invention suppresses the Si content to the lowest range for a hypereutectic type and controls the crystallization of primary Si, thereby achieving excellent wear resistance of a hypereutectic type high-silicon aluminum alloy. It is an object of the present invention to provide an aluminum alloy that suppresses deterioration in machinability and impact resistance while maintaining the following properties.

B0 Structure of the Invention +11 Means for Solving the Problems The wear-resistant aluminum alloy according to the present invention has Si 12.0 to 14.
0% by weight, Cu 4.0-5.5% by weight, Mg0.5
~1.5% by weight, Ni0.5~1°5% by weight, Ti
0.1-0.25 wt%, Ca0,0 O50 wt%
Hereinafter, it is characterized by being composed of 0.0010% by weight or less of Na, the balance being Al and unavoidable impurities.

(2) Function The reason for limiting the function and content of each chemical component in the present invention is as follows.

Si is a chemical component necessary to improve wear resistance, strength, and castability, but if its content is less than 12.0% by weight, sufficient wear resistance etc. cannot be obtained; If the content exceeds 14.0% by weight, the amount of hard primary Si crystallized will be excessive and machinability, impact resistance, and toughness will deteriorate. Therefore, the Si content is 12.0 to 14.
It is limited to a range of 0% by weight.

Cu is a chemical component that contributes to solid solution hardening and age precipitation hardening, and is also a chemical component that contributes to AI! - Lower the eutectic point of Si-based alloys
It has the function of improving wear resistance by moving the primary Si to the side and increasing the area ratio of primary Si. Therefore, the Cu content is limited to the above range.

Mg and Ni have the function of improving strength and toughness by applying heat treatment after casting the part, but this
This is obtained when the content of both Mg and Ni is set in the range of 0°5 to 1.5% by weight, and therefore Mg
The content of Ni is limited to the above range.

Ti is a chemical component necessary to refine macrocrystal grains and improve tensile strength, but if its content is 0.
If the content is less than 1% by weight, the effect of refining the crystal grains will be small, while if the content exceeds 0.25% by weight, coarse acicular Al-T will be produced.
The i-Si compound crystallizes, resulting in a decrease in toughness and little effect on improving tensile strength. Therefore, the Ti content is limited to a range of 0.1 to 0.25% by weight.

Ca and Na have the function of moving the eutectic point of the AJ-Si alloy to the high Si side and preventing the crystallization of primary Si.
The Ca content is 0.0050% by weight or less, and the Na content is 0.0050% by weight or less. By setting each content to ooiowt% or less, the amount of primary Si crystallized can be controlled to an appropriate amount.

Since Fe and other impurities cause a decrease in the toughness of the aluminum alloy, it is desirable to suppress them to 0.5% by weight or less.

The heat treatment conditions are the same as those normally applied to this type of alloy, thus solution treatment at 500-510°C for 1-2 hours, and artificial aging at 240-250°C for 5-10 hours. Each time will be held.

(3) Examples The table below shows the present invention alloy A and two conventional alloys B (JIs
The chemical components and contents of ACBC material) and C (JIS ACQB material) are shown.

Castings were cast from the alloy A of the present invention and conventional alloys B and C using a JTS No. 4 boat bottom mold, and the castings were heated to 505°C.
After solution treatment for 3 hours at
Artificial aging treatment was performed at 0°C for 5 hours.

Figures 1 (A) to (C) show alloy A of the present invention and conventional alloy B.
, C show cross-sectional micrographs (200x magnification) of the casting material obtained from C, and the relatively large black dots are primary Si crystals.

In the alloy A of the present invention shown in FIG. 1(A), it is clear that an appropriate amount of primary crystal Si having an appropriate particle size is uniformly dispersed and crystallized. In the eutectic type conventional alloy B shown in Fig. 1(B), there is no crystallization of primary Si, and in the hypereutectic type conventional alloy C shown in Fig. 1(C), no primary crystal Si crystallizes. The amount is large, and their particle size is also coarse. .

FIG. 2 shows the results of test pieces cut from casting materials obtained from alloy A of the present invention and conventional alloy B, and subjected to a large mirror friction and wear test on the test pieces. The test conditions were dry, a disk made of JIS Fe12 material was used as the mating material, and the rotation speed of the disk was set at two speeds: low speed and high speed.

It is clear from FIG. 2 that the base metal A of the present invention has superior wear resistance compared to the conventional alloy B.

FIG. 3 shows the results of measuring cutting resistance of test pieces of alloy A of the present invention and conventional alloy B in order to investigate machinability. The measurement method was to use a diamond cutting tool on a high-speed lathe, keep the cutting speed, depth of cut, and feed rate constant, perform repeated cutting three times without lubrication, and measure the cutting resistance each time. 3 (1) to (3) correspond to the first to third cutting operations, respectively. In the figure, a indicates the principal component force, b indicates the feed component force, and C indicates the backward force, and the unhatched portions indicate before cutting, and the hatched portions indicate after cutting.

From FIG. 3, it is clear that the increase in cutting resistance of the alloy A of the present invention is smaller than that of the conventional eutectic type alloy B, and the decrease in machinability is small.

C0 Effects of the Invention According to the present invention, by specifying various chemical components and their contents, it is possible to provide an aluminum alloy that has excellent wear resistance and suppresses deterioration in machinability and impact resistance. It is something.

[Brief explanation of the drawing]

Figures 1 (A) to (C) are micrographs of the alloy of the present invention and two types of conventional alloys, Figure 2 is a graph showing the wear test results of the alloy of the present invention and the conventional alloy, and Figures 3 (1) to (
3) is a graph showing the machinability test results of the present invention alloy and the conventional alloy. A: Invention alloy, B: Conventional alloy. . )1' (A) (B) Figure 3 Name 1 Figure 2 ztj Platform TA Platform 1N Go November 1, 1980 1. Indication of the case 1982 Patent Application No. 147329 2 Name of the invention Wear-resistant aluminum alloy 3 Person making the amendment Name of the patent applicant related to the case (532) Honda Motor Co., Ltd. Address
1st Nijimura Building 5, 4-4-5 Shinbashi, Minato-ku, Tokyo
Date of amendment order: October 9, 1980 (Shipping date: October 30, 1982)
6. Contents of amendment in Column 7 "Detailed Description of the Invention" and "Brief Description of Drawings" of the specification subject to amendment ~Page 8, line 4 is corrected as follows. Figure 1 (A to (0) shows micrographs (200x magnification) showing the metallographic structure of the casting materials obtained from the present invention alloy A and the conventional alloy B. The relatively large black dots are primary crystals. It is clear that in the alloy A of the present invention shown in Figure 1 (74), an appropriate amount of primary Si with an appropriate particle size is uniformly dispersed and crystallized. In the conventional alloy B of the crystal type, there is no crystallization of primary Si, and in the conventional alloy C of the hypereutectic type shown in Fig. 1 (Q), the amount of primary Si crystallized is large, and the grain size of 2.Page 9, line 14 of the specification..."Conventional alloy"......"
This is corrected as "It shows the metal 1 structure in conventional alloys."that's all

Claims (1)

[Claims] Si12.0-14.0% by weight, Cu4.0-5.5
% by weight, Mg 0.5-1.5% by weight, Ni 0.5-1.
5% by weight, Ti0.1-0.25% by weight, Ca0.00
50% by weight or less, Na0.0010% by weight or less, balance A
A wear-resistant aluminum alloy consisting of l and inevitable impurities.