Research On Prepartion Of Laminar Metal Matrix Composites Based On Mo/Ag Immiscible Alloy System Using Irradiation Damage Diffusion Alloying Mechanism

conductive property. But its ability against Low Earth Orbit (LEO) space environment is insufficient, so it can not meet the needs of long-term on-orbit service for the space vehicle. As Mo/Ag Laminar metal matrix composites have characteristics such as high strength, high specific modulus, and low coefficient of thermal expansion, its thermal and electrical conductivity, wear resistance, high temperature resistance and fatigue resistance are good, which is very suitable for LEO space craft under alternating thermal force.Because Mo-Ag is not a solid solution metal system, the heat of formation is positive, and diffusion between them is difficult, thus preparation of Mo/Ag Laminar metal matrix composite is difficult. In light of this, this paper puts forward a new irradiation damage diffusion alloying mechanism. Based on the alloying mechanism, using pure Mo foil as metal matrix, adopting etch, ion implantation and composite penetrating masonry, we prepared the Mo/Ag Laminar metal matrix composites successfully and obtained the following results.(1) After conducting single point resistance spot welding between the prepared composite materials and space gallium arsenide/ge solar cell, the largest welding tensile strength is 460 gf, and the average level is 430 gf. This meets indicators requirements proposed by the national military standard and space users.(2) Systematic research was done on the influence of each technological parameter on interface strength of the Mo/Ag Laminar metal matrix composites. The result shows that prolonging the time of etching process, silver ions composite plating, annealing and raising temperature are in favor of the improvement of the interface strength of the Mo/Ag Laminar metal matrix composites.(3) Mo/Ag diffusion (interface) layer was characterized by high resolution transmission electron microscopy (HRTEM), and the result shows that the key of forming metallurgical combination on Mo/Ag interface lies in the formation of amorphous alloy phase.(4) The HRTEM and positron -electron annihilation (PAT) results show that, the diffusion between Mo-Ag is likely caused by vacancy movement. This paper provides a new method for the preparation of not compatible solid solution system laminar metal matrix composites. The using of prepared Mo/Ag laminar metal matrix composites for LEO space vehicle will effectively improve its on-orbit life and reliability.