Reseach On Preparation Of Mo/Ag Series Laminar Metal Matrix Composites Using Irradiation Damage Alloying Method

Ag has often been used as interconnector of solar cell array in space flight due toits excellent toughness, conductivity and good weldability. But its ability thatwithstands space environment in Low Earth orbit (LEO) is insufficient; it can’t meetthe requirements of long-term in-orbit service for space vehicle. And Mo/Ag serieslaminar metal matrix composites which has excellent heat shock, conductivity andweldability, et al, and has the resistance for atomic oxygen (AO)and no magnetic isvery suitable for the LEO spacecraft carrying alternating thermal load and the atomicoxygen (AO) erosion.For above preparation difficulty, the research has put forward a kind of "no solidsolution alloying metal irradiation damage mechanism", solving the problem of thelayered composite of Mo/Ag. In the article, it is still necessary that adopts the methodof “irradiation damage alloying” to enhance the strength of composite material layerinterface (especially the strength of the interface between the Mo/Pt). Based on thisidea, Mo/Pt/Ag laminar metal matrix composites is prepared successfully and itsinterface between the laminas has been mutual diffusion and implementedmetallurgical bonding to ensure that the interface has high bonding strength.In addition, in this paper, it was revealed that adopts the vacuum evaporateplating Ag technology solved the problem, in poorer resistance spot welding strengthstability between Mo/Ag laminar composites and space solar cells. So it can bepractically applied in the model.Finally, the diffusion mechanism of irradiation damage metals alloying indynamics was researched by slow positron annihilation Doppler broadening test in thestudy.We obtained the following results:(1) Using vacuum evaporate plating Ag technology solves the problem ofresistance spot welding strength stability between Mo/Ag laminar composite materialsand space solar cell, the composite material can be practical applied in the model.(2) Studied the influence factors on the interface tensile bonding strengthbetween laminas of Mo/Pt/Ag laminar metal matrix composites, the results show thatis still necessary and efficient adopting the method of “irradiation damage alloying” toenhance the strength of composite material layer interface due to the low Mo metalsurface activity. Meanwhile, different plating method, annealing temperature andprotective atmosphere had effect on the interface tensile bonding strength. The tensile bonding strength of resistance spot weld connection between the Mo/Pt/Ag andMo/Ag laminar metal matrix composites and the solar cell in space flight was up to500gf, and an average of was up to360gf. Its performance can meet the request ofnational military standard GJB2602-1996and users.(3) In this work, qualitative and quantitative determination of irradiation damagestructure produced by bombardment of ion implantation was researched with slowpositron annihilation Doppler Broadening (DB); it revealed the situation of irradiationdamage and the changing rules with annealing temperature.