JPS58100654A - Aluminum alloy for casting with superior heat resistance - Google Patents

Abstract

PURPOSE:To obtain an Al alloy with superior heat resistance and castability by adding specified amounts of Si, Cu, Mg and V and/or Mo to Al. CONSTITUTION:The composition of an Al alloy is composed of, by weight, 8-13% Si, 2-5% Cu, 0.2-0.8% Mg, 0.05-0.5% V and/or 0.05-2% Mo and the balance A with inevitable impurities. Thus, by further adding V and/or Mo to an Al-Si-Cu-Mg alloy, the heat resistance of the alloy is remarkably enhanced. In case of <0.05% each of V and Mo, the effect of enhancing the heat resistance is not sufficiently produced, and in case of >0.5% V and >2% Mo, uniform solubilization is made difficult.

Description

[Detailed description of the invention] This invention! j! relates to an aluminum alloy for casting with excellent heat resistance.

In recent years, in the automobile industry, there has been a demand for lighter vehicle bodies as part of energy-saving measures9, and efforts are being made to use aluminum for various parts. However, materials such as cast iron are still used for moving parts that require excellent mechanical properties at high temperatures, especially where weight is an issue.

A type of conventional heat-resistant aluminum alloy that has been used relatively frequently: fXB HjJOJ (AO#A).

MUORB, MU020) are both AJ-
81-Ou-Mg based alloys, including MuOtmu and MuO
IB also contains nickel and is mainly used for pistons, but it does not have the heat resistance to fully replace heat-resistant parts made of iron-based materials. If there is an aluminum alloy with high heat resistance strength, parts conventionally made of iron can be replaced with aluminum alloy castings with high heat resistance strength, and as a result, weight can be reduced.

Based on the above-mentioned current situation, the present inventors have undertaken research and development of a material that has higher high-temperature strength than known heat-resistant aluminum alloys and has good castability, and as a result of repeated research, has found that Without this, we succeeded in developing a material with high high temperature strength.In other words, the present invention has silicon I~/3Ls by weight.

Steel, o-jt14, magnesium 0. Excellent heat resistance, containing J~o,r, occasionally containing one or both of elements selected from vanadium O, Oj~00j- and molybdenum O, Oj~, o%, with the balance being aluminum and impurities. It is an aluminum alloy for casting.

In the present invention, each of the contained components is limited as described above, and the reason is as follows.

Silicon is an essential component for improving the castability of aluminum alloys, and is also effective in improving heat resistance. However, if it is less than t, it will be difficult to maintain good castability and the high temperature strength will not be sufficient. Also/3e
If it exceeds s, it is undesirable because it reduces the toughness of the alloy.0 Copper is effective in imparting heat treatability to the alloy and increasing the strength of the material.If the content of copper is less than -00 Sufficient strength cannot be obtained, and if it exceeds 5%, castability tends to deteriorate.

Magnesium, like copper, significantly enhances age-hardening tubes through heat treatment. If the magnesium content is less than 0,000 yen, the precipitation of Mg81 will not harden sufficiently, and therefore high strength will not be obtained. Moreover, if it exceeds 0.1, the toughness decreases and the alloy becomes brittle.

In the present invention, the above A No. 81-0u-M
By further containing vanadium and/or molybdenum in the g-based alloy, the heat resistance strength of the alloy is significantly improved. The effect of vanadium is not sufficient if it is less than O, osqlr, and if it exceeds O, S%t-, it becomes difficult to dissolve uniformly, and even if it is added, there is no significant change in its heat resistance strength. O also in the case of molybdenum
If it is less than ,OS-, the effect of improving heat resistance strength will not be sufficient, and if it exceeds 0,0St-, uniform dissolution will be difficult, and even if it can be added, the effect will not be significantly improved.

In the casting of the alloy of the present invention, 0,
There is nothing wrong with adding less than 3 moss of titanium and/or less than 000s of boron to refine the alloy th.

In addition, it is preferable to use the cast metal after heat treatment,
General τ5 processing or Tt processing can be adopted.

Next, the present invention will be explained in more detail with reference to examples.

Example 1! 1% This shows the chemical composition of the present invention alloy and a known heat-resistant aluminum alloy for comparison. In addition, among the components in Table 1, iron (F@) d is mixed as an impurity. After heat treatment, the obtained ingot was processed into No.fN841 tensile test piece and high temperature tensile test piece, which were subjected to tensile test and hardness measurement at room temperature and tensile test and hardness at high temperature (JOOC). All heat treatments used in the measurements were performed at T6 for 31 sessions, and the conditions were as follows:
After solution treatment for jOOCx♂ hours, water quenching is performed,
Immediately, each piece was tempered for 41 hours at 0C.

The conditions of the high temperature tensile test are 2 at 00C after the specified T1 treatment.
A test piece that was continuously heated for 00 hours and once naturally cooled to room temperature was set in a high-temperature tensile test device, and a tensile test was conducted while holding it at 50°C for 30 minutes. If the high temperature hardness is 9, is the test piece after high temperature tensile test? The chuck portion was placed face side and measured using a Brinell hardness meter, and the measurement temperature itself was room temperature.

Table 1 shows the results of tensile tests and hardness measurements at room and elevated temperatures.

As can be seen from Table 2, the alloy of the present invention has significantly improved high temperature strength compared to known alloys.
Compared to conventional heat-resistant alloys represented by ), the tensile strength at high temperatures, O, Co yield strength, and hardness are approximately 30 times higher.

As described above, the alloy of the present invention has unprecedented high-temperature strength Wi and is a completely new material with excellent castability. Therefore, a car? It is expected to have a wide range of uses as a material for parts that require heat resistance, such as those around the engines of other industrial machinery.

Claims (1)

[Claims] Contains by weight silicon l~/3-1 copper co-Q-j%% magnesium O, co~0.14 f, and further vanadium o
, oj~o, s % and molybdenum o, oj~ko, O
An excellent heat-resistant aluminum alloy for casting containing one or both of the following elements, with the balance being aluminum and impurities.