The Study Of Beryllium And HR-1Stainless Diffusion Bonding

Metal beryllium has widely applied to industry of nuclear, space flight and airplane due to the characteristic of low density, high strength ratio, high specific heat and excellent property of heat. But beryllium's high brittleness and low ductibility bring its component's design much difficulty. Furthermore, beryllium is an active element, which is prone to be oxidized especially at high temperature and react with many other metals to form brittle intermetals, which influence the component's use and life. Bonding beryllium with HR-1 stainless has important significance and great-applied value, but the numbers .It has been showed aboard that it is very difficult to bond beryllium with stainless steel due to weld stress and crackle resulting from brittle inter-phase has not studied it in China. Diffusion bonding and brazing may be good methods to bond beryllium with HR-1 stainless successfully, but choosing the perfect technological parameter, interlayer and characterizing bonding interface for bonding be with HR-1 stainless have great difficulty. The diffusion and brittle-phase formation mechanics is ambiguous, and the model of diffusion concentration field isn't reported in document. So researching the diffusion bonding between be and HR-1 stainless plays an important role in production and practice, especially studying the relationship among diffusion bonding technics, component, structure and performance. In this paper, Be and HR-1 stainless steel are bonded by diffusion bonding and brazing. The following conclusions may be obtained:1)X- radial phase analysis after peeling shows that the diffusion bonding area consists of α-Be mostly and a little intermetals, such as Be11Fe, Be5Fe, FeBe2, Be21Ni5, Be12Cr,MoBe12 etc.α-Fe and BeO also exist。2) The microstructure in the diffusion bonding area forms three white area, a dark area and three area in which white and black coexist.3) The white area mainly consists of intermetals and them distribute on grain boundary. In the dark area ,α-Be is the most component. While the white and black coexisting area is two phase area. 4) The sidesteps in the AES correspond with intermetals.5) The diffusion bonding area become much brittler and has high hardness and good capability to corrosion because of intermetals and solid solution existing. 6) During the process of hot pressing, the diffusion rate on the grain boundary is bigger than the inner grain ones. The intermetals mainly lie on grain boundary.7) The simulation of concentration profile for the HIP and hot pressing specimen accords with the experiment profile. The computer is a good tool to optimize technology parameters.