Method for improving ductility of casting beryllium aluminum alloy

Abstract

The invention discloses a method for improving ductility of casting a beryllium aluminum alloy. The method comprises the following steps that (1) polishing is carried out on the surface of a casting,and when impurities in the surface is removed, the casting is put into a hot isostatic pressing furnace; (2) an initial pressure is stamped into the furnace, wherein temperature is heated to 500 DEG Cwith a heating rate which is less than or equal to 5 DEG C / min and kept for 30 minutes; (3) the temperature is continuously heated to 590 + / -10 DEG C at the same heating rate, a hot isostatic pressing treatment pressure is enabled to be 110-130 MPa, and the treatment time is 150-180 minutes; and (4) after the treatment is completed and the temperature is cooled to 200 DEG C with the heating ratewhich is less than 5 DEG C / min, and power-off and the cooling are carried out. According to the method, a medium used for the hot isostatic pressing is argon, the performance of a beryllium-aluminum alloy phase interface is improved after the casting is treated through the hot isostatic pressing, the strength and the ductility rate of the alloy are improved, certain casting defects in a casting product after the treatment are improved, and the compactness of the alloy is further improved; and the strength of the alloy treated by the hot isostatic pressing is increased by about 10%, and the ductility rate is improved by 60% or above.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to a method for increasing the elongation of cast beryllium aluminum alloy. Background technique [0002] Beryllium aluminum alloy (containing 60-70% beryllium) has the advantages of rigidity of beryllium and toughness of aluminum. It has light weight, high specific strength, high specific stiffness, good thermal stability, high toughness, high modulus, corrosion resistance, etc. It is an important new structural material. Beryllium aluminum alloy also has excellent thermal and optical properties, and has been widely used in aerospace electronic equipment and high-mode frequency equipment. At the same time, beryllium aluminum alloy has very strong competitiveness in civilian fields such as computer manufacturing, automobile industry and high-precision, high-speed electric welding machine manufacturing. [0003] Investment casting technology is the main preparation method...

AI Technical Summary

Problems solved by technology

Moreover, the melting points of the two metals, beryllium and aluminum, differ by nearly 600°C. Beryllium aluminum alloy has a wide solidification temperature range, starting from about 650°C, which causes the problem of metal feeding, and also causes shrinkage defects and pores in the final product.

In the process preparation, the method of adding a third element is generally used to improve the castability of the alloy to improve the casting quality and product performance. However, the performance of the cast beryllium aluminum alloy is still difficult to meet the needs of customers. The main performance is that the product strength is low and unstable. low elongation

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