Papers by Author: Peng He

Abstract: Distribution of Zn and interfacial microstructure of braze-welding CMT joints between aluminium and galvanized steel sheets were researched. The results showed, except the gas porosity contains a little Zn, the other areas of fusion zone almost have no Zn. Temperature plays a decisive role in the distribution of Zn. The content of Zn is higher in the dendritic crystal than the intergranular part. The Zn coat adjacent to the joint is almost evaporated entirely. The Zn coat of steel sheet in the heat-affected zone around the joint is badly destroyed, and the corrosion resistance of the joint will decline. There are FeAl3 intermetallics and Al-Fe-Zn triphase solid solution formed at the interface.

Abstract: Distributions of residual stress in diffusion bonding of dissimilar materials intermetallics TiAl to steel 40Cr were simulated by FEM calculation. Results showed that destructive residual stresses presented in the minute area adjacent to bond-line of the base material with the smaller thermal expansion coefficient. Reducing bonding temperature and diminishing bonding time are in favor of the mollification of interface tresses. Concepts of the residual stress factor Rf and the thickness factor Tf were propounded. As selecting the interlayer, the interlayer with smaller |Rf| and Tf should be given precedence, and with a prerequisite of sufficient physical contact small thickness of the interlayer are finer.