Preparation method of in-situ synthesized aluminum-based composite bar

Abstract

The invention discloses a preparation method of an in-situ synthesized aluminum-based composite bar. The preparation method comprises the steps of preparing TiB2 reinforced aluminum-based composite billet by adopting a mixed salts method; installing and welding the aluminum-based composite billet to form a consumable electrode with the cross section of Phi 150-500mm; then, smelting to obtain a vacuum consumable ingot of Phi 200-600mm; feeding the vacuum consumable ingot into a resistance furnace, heating, preserving the heat, and forging the vacuum consumable ingot to obtain the aluminum-based composite bar with the cross section of Phi 150-500mm. Through microscopic and macroscopic metallographic inspection, the aluminum-based composite bar prepared by using the preparation method is very uniform in TiB2 reinforced phase distribution and very compact in tissue; and through ultrasonic inspection, the bar has no inclusion defect and has the tensile strength of 415MPa and the rupture elongation of 2.5%.

Description

technical field [0001] The invention belongs to the technical field of metal matrix composite materials, and relates to a preparation method of a metal composite material, in particular to a preparation method of an in-situ self-generated aluminum matrix composite material bar. Background technique [0002] Materials used for key components in aerospace vehicles, space devices, space exploration and other systems are required to have comprehensive properties such as high specific strength, high specific modulus, high thermal conductivity, low thermal expansion, and high thermal deformation resistance. It is difficult for traditional single metal, polymer and ceramic materials to meet such high comprehensive performance requirements. The discontinuous reinforced aluminum matrix composite material composed of high-performance reinforcements (particles, whiskers, short fibers) and aluminum alloys, both It has the excellent properties of aluminum alloys, and can obtain the requi...

AI Technical Summary

Problems solved by technology

ZL200310122739.1 and ZL200510028209.X introduced the preparation of in situ self-generated aluminum matrix composites by mixed salt method, however, these methods only solved the problem of uniform distribution of reinforcement phase in the molten state of composite materials

Because the composite material in the molten state repells the reinforcement phase to the grain boundary during the crystallization process, the reinforcement phase is enriched and segregated, resulting in the inhomogeneity of the composite material, which greatly deteriorates the material properties.

Especially when large bars above Φ150mm are to be produced, due to the use of conventional casting molds such as sand sleeves, the solidification of the composite material in the molten state is very slow, and the uneven reinforcement phase in the composite material is very serious. Due to simultaneous solidification, defects such as shrinkage porosity and shrinkage cavities are easily formed in the center of the material, and the slag inclusions in the material are difficult to float out of the surface, and the quality of the ingot is difficult to control