The interfacial shear strength of SiC fiber reinforced aluminum composite has been studied by the fragmentation test of single fiber reinforced model specimens after a number of fatigue cycles. The result shows that apparent stiffness of the testing machine is influenced by cyclic loading, which will affect the calculation of fiber strength by Clough's model. An extracting test in which fragmented fiber was extracted out by dissolving the matrix material in NaOH water solution indicated that the fiber strength did not lose via vacuum hot press treatment. This result contradicts the Clough's model. The experimental result showed that the critical length of the fiber increases a little after a few cycles of fatigue loading and thus, the interfacial shear strength decreases. The reason for this is that the thermal residual stress around the fiber developed during fabrication decreases in cyclic loading.

A low-Co Ml0:8Mg0:2Ni3:2Co0:3Al0:3 alloy was prepared and investigated by examining the alloy structure, phase composition, hydrogen absorption/desorption and electrochemical properties. The alloy is composed of Mg-free LaNi5 phase as matrix and Mg-contained LaNi3 phase as secondary phase. The hydrogen storage capacity (1.37wt%) at 298K, discharge capacity (320mA h=g) and cycling stability (where 88% of the initial capacity remained after 300 charge/discharge cycles) of the alloy are as good as those of the commercial MmNi3.55Co0.75Mn0.4Al0.3 alloy. However, the high-rate discharge ability is better than that of the commercial alloy. The Mn-free composition is advantageous to the oxidization-resistant performance of the alloy. The secondary phase is tougher than the matrix, which not only contributes to the high-rate discharge ability, but also improves the fracture ductility and depresses the disintegration during charge/discharge cycle.

1.4%C ultra high carbon steel (UHCS) was prepared in order to study the substructure of martensite transformation. Because of ultra-fine spherical carbide, the growth of austenite grain, whose average size was 2.5μm, was prohibited. After quenching, there was a great deal of lath martensite. The sub-structure was composed of a large quantity of dislocations and twins. Through calculation, it was determined that twin shear stress increases faster than that of slip due to the reduction of austenite grain sizes. A model based on twin and slip shear stresses has been proposed, which yields critical grain size ranges from 1-4μm. The result is in agreement with measured results.