MECHANICAL PROPERTIES OF Si3N4/METAL DIFFUSION WELDING TIP
(1. Beijing General Research Institute for Non ferrous Metals; Beijing 100088 ；
2. University of Science and Technology Beijing; Beijing 100083)
2. University of Science and Technology Beijing; Beijing 100083)
Abstract: The mechanical properties of Si3N4/metal-diffusionwelding tip produced by thermal vacuum pressure diffusion welding with pure Al as transition layer were studied. The results show that when temperature, pressure, holding time and cooling rate of diffusion welding are 600℃, 80 MPa, 30 min and 2℃/min respectively, the maximum of the shear rupture strength of the tip is 112.6 MPa. Fracture takes place very easily 1 mm along the Si3N4 side of the welding seam. The thermal residual stress comes from the thermal expansion difference between Si3N4 and metal. Metallurgical bond forms between Si3N4 and metal by interfacial reaction between Al transition layer and Si3N4, metal respectively.
Key words: mechanical property diffusion welding Si3N4/metal thermal residual stress