In order to research welding technology of DX51D+Z cold rolled galvanized steel, using multivariate nonlinear regression orthogonal combination design method, adopted the shear load as quality indicators, counted welding current, electrode force, welding time, squeeze time and the interaction of them as factors, to built the nonlinear regression models, by adopting this model to forecast shearing load. The result shows that this model has high forecast precision.

In order to research welding technology of DX51D+Z cold rolled galvanized steel, using multivariate nonlinear regression orthogonal combination design method, adopted the shear load as quality indicators, counted welding current, electrode force, welding time, squeeze time and the interaction of them as factors, to built the nonlinear regression models, by adopting this model to forecast shearing load. The result shows that this model has high forecast precision.

Powder of Ti-46at%Al alloy was synthesized through mechanical activation (MA) and then sintered and concurrently consolidated in a short sintering time of 900 s by using spark plasma sintering (SPS) process. The XRD and SEM profiles show that the microstructures of TiAl alloys contained γ TiAl and small amount α-2 Ti3Al phase, whose amount can be controlled by the sintering temperature. The compacts retained the original fine-grained fully densified bodies by avoiding an excessively high sintering temperature. The alloys sintered at higher temperature with this process showed a coarser microstructure. So it is possible to produce dense nanostructured TiAl alloys by mechanically activated spark plasma sintering (MASPS) within a very short period of time.