| Metal beryllium is the rare metals, and is widely applied to industry of nuclear, aviation and spaceflight 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 make its component design and producing much difficulty. Furthermore, beryllium is an active element ,which is prone to form brittle inter-metals, which influence the component's use and life. So researching the diffusion bonding in the hot pressing between Be and HR-1 stainless steel plays an important role in theory and practice, especially studing the relationship among diffusion bonding technique, components, structure and performances.The components, structures and performances of diffusion bondings in the hot pressing of Be/HR-1 stainless steel, Be/Cu/HR-1 stainless steel, Be/Al/HR-1 stainless steel and Be/Ag-Cu/HR-1 stainless steel have been studied in this item, the conclusions are as follows:①D uring the process of hot pressing of Be/HR-1 stainless steel, Fe and Be form incomplete solid solution with very little solubility limit. Therefore the dominating way is diffusing along the grain boundaries, and brittle inter-metallic compounds form mainlyon the grain boundaries.②D uring the process of hot pressing of Be/Cu/HR-1 stainless steel, the solubility limit of Cu in Be is larger than in Fe. Therefore Cu diffuses into the Be not only along the grain boundaries but also through the grains, while diffuses along the grain boundaries largely in the stainless steel, which is why there is an obvious asymmetry diffusion of Cu into Be and stainless during the hot processing.③T he solubility limit of Al in iron is about 20%(atom%)at room temperature , whereas it does not dissolve in Be and they form eutectic. So during the process of hot pressing of Be/Al/HR-1stainless steel, Al diffuses into the iron not only along the grain boundaries, but also throughout the grains, which diffuses mainly along the grain boundaries in the Be.④D uring the process of hot pressing of Be/Ag-Au/HR-1 stainless steel,the solid solubility limit of Cu in Be is larger than that of Ag in Be, so it is easier for Cu to diffuse into Be, which leads to separation of Ag and Cu in Ag-Cu alloys and asymmetry diffusion of intermediate layer into the two sides. ⑤A fter hot pressing, there are lamellar structures in Be/HR-1 stainless steels and Be/interlayer/HR-1 stainless steels, and the lamellar layers are almost perpendicular to the outside forces direction, with the layers almost paralleling to each other.⑥During the process of hot pressing of Be/HR-1 stainless steel, Be-Fe, Be-Ni, Be-Cr and so on inter-metallic compounds are formed, while during the process of hot pressing of Be/interlayer /HR-1 stainless steel, elements of interlayer and matrix as well as between two matrix materials form inter-metallic compounds. Inter-metallic compounds form mainly on the grain boundaries.⑦Fractures of Be/HR-1 stainless steels and Be/interlayer /HR-1 stainless steels both are brittle.⑧T ensile strength of Be/Ag-Cu/HR-1 stainless steel is most among the tested materials, as followed by that of Be/Cu/HR-1 stainless steel and Be/HR-1 stainless steels.⑨Elements of chosen interlayer materials should form solid solution or eutectic with that of matrix materials as possible in order to avoid the formation of brittle inter-metallic compounds.⑩Pressure not only makes the contact areas of connected interface enlarge gradually but also cause dynamic formed re-crystallization and diffusion creep, which affects diffusion ratio of diffusion welding zones and grain size. Matrixes or diffusion welding zones may form texture under pressure of a single axle direction.⑾The simulation of concentration profile of hot pressings specimens can accords with the experimental profile. The computer is an important tool toptimize the hot processing parameters.
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