Papers by Author: Fang Fei Dong

Abstract: In this study, a numerical model was built to simulate the self-piercing riveting (SPR) process using commercial LS-DYNA finite element code. The difficulties in numerical simulation of the SPR process, such as large deformation and fracture, were resolved by the use of an explicit solution process combined with the r-adaptive meshing method. The model was applied to joining two sheets of 6061 aluminium alloy. The effects of die geometry, rivet material properties and the adaptive step size in numerical calculation were studied, using 6061 aluminum sheets as a model system. The simulation agrees well with the experimental results in terms of geometric characterisitcs of the cross-sections of the joints formed.

Abstract: The custom-designed amorphous brazing filler metals in foil form has been developed for application in brazing stainless steel 0Cr18Ni9. The new alloys contains 10.5wt% chromium, 5.4wt% silicon, 1.5wt% boron, 3wt% cobalt and nickel as the balance. The melting range is within 971°C1070°C. The alloy exhibits good melting characteristics and wetting behavior. With a 25μm thick foil, the joint is free of brittle central eutectic phases inside the joint via diffusion of the alloying elements into adjoining base metal and results on a high mechanical joint strength.