SiC enhanced aluminum-based composite material for spacecraft and preparation method thereof

Abstract

The invention discloses a SiC enhanced aluminum-based composite material for a spacecraft and a preparation method thereof. The composite material consists of the following chemical ingredients in percentage by weight: 23 to 35 percent of SiC, 26 to 35 percent of Si, 1.8 to 2.0 percent of Mg and the balance of Al and inevitable impurities. The method comprises the following steps of: performing surface treatment of powder, performing high-energy ball-milling mixing under vacuum by a wet method, and performing hot pressed sintering under the vacuum. The thermal expansivity and density of the material can be reduced effectively and the tensile strength can be improved by controlling the addition of the SiC and an alloy element Mg and a preparation process, so that the composite material which is low in cost and high in corrosion resistance and of which the thermal expansivity is 7 to 9*10<-6> / DEG C, the density is less than 2.7 g / cm<3> and the tensile strength is more than 230 MPa is obtained. The SiC enhanced aluminum-based composite material is particularly suitable for aerospace parts which are light in mass, low in expansion and resistant to corrosion and have certain strength.

Description

technical field [0001] The invention belongs to the field of metal matrix composite material manufacturing, and in particular relates to a SiC reinforced aluminum matrix composite material used for spacecraft and a preparation method thereof. Background technique [0002] In the design of spacecraft, dimensional stability is widely used in high-precision instruments, inertial platforms and other fields. Due to the large range of temperature changes in the working environment and the needs of the instrument itself, especially some optoelectronic equipment, it is required that the materials used should be stable when the temperature changes. The dimensional change is very small, which requires the thermal expansion coefficient of the material to be very small, or even zero; the material needs to have stable tensile strength, and the cyclic thermal stress is required to be very small. In order to increase the payload of the spacecraft, it is necessary to further reduce the dens...

AI Technical Summary

Problems solved by technology

Cu / Mo alloy and Cu / W alloy have high thermal conductivity and matching thermal expansion coefficient, but the price of Mo and W is high, the processing and welding performance is poor, and the density is high, so it is not suitable for application in the aerospace field

[0004] As a hotspot in the research of composite materials, there are many research results on SiC reinforced aluminum matrix composite materials published in the world at home and abroad. However, due to the large difference in thermal expansion coefficient between SiC and aluminum or its alloys, large residual stress remains in the structure. The follow-up processing is complicated, and it is easy to cause thermal cycle stress in the working environment, which affects the stability of material strength