The physical pattern and mechanical property of residual binder film on the used sodium silicate sand under different temperature were studied by the numbers.

In this Paper the joint profile expression and fractal theory are reviewed, and the fractaltheory is used to study the frictional angle of the rock joint.

The effect of RE and heat treatment on eutectic carbide morphology and impact toughness of white cast iron was studied.

The effects of improving white cast iron carbide morphology on the amount of modificator,solidification speed carbide equivalent,the time and temperature of modification such as other technological factor.

The shape of the sample’s surface compound layer after nitrocarburizing with catalytic permeation was studied and the effect of test temperature,atmosphere and steel composition on the shape of the compound layer was discussed.