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The multi-pass hot compressive tests of Ti-6Al-4V alloy prepared by hot isostatic pressing were carried out. The results show that the flow stress with the strain rates of 1s−1 and 5s−1 both in first-pass at 1050°C and second-pass at 1000°C deformation, also with the strain rate of 5s−1 in third-pass at 950°C deformation, exhibit obvious dynamic softening behavior. For first-pass deformation with the strain rate ranging from 0.001s-1 to 0.1s-1, a few equiaxed β grains can be observed and the larger strain rate resulted in the smaller dynamic recrystallization (DRX) grains. For second-pass deformation, a number of finer DRX β grains and a few DRX α grains can be observed under 0.01s−1 strain rate. The grain boundary is indistinguishable and a small number of DRX grains adhere to the grain boundary under 0.1s−1 and 1s-1 strain rates; there are plenty of lamellar α structure and a few basketweave structures. For third-pass deformation, there are equiaxed β grains and equiaxed primary α grains under 0.1s-1 strain rate. Moreover, a small number of globularization α grains can be observed. As the strain rate increasing to 1s-1, a great many of interlaced fine lamellar α phases precipitated inside the β grain.

The microstructure evolution of Mg-Gd-Y-Nd-Zr heat-resistant magnesium alloy after deformation and T5 or T6 treatment were studied. In thermoplastic deformation, dynamic recrystallization and dynamic precipitation has been taken place at the same time. The dynamic precipitation reduces the recrystallization nucleation driving force in the grain; it will prevent to occur dynamic recrystallization partially. Solid solution temperature was 530oC and hold 4h. Age hardening treatments were performed at 225oC and hold 16h. The alloy showed the comprehensive properties are obviously improved from T6 to T5 heat treatment. After T5 heat treatment the tensile strength of alloy increased to 359.3 MPa, increased by around 48.5%; Elongation is increasing from 5.17% to 6.5%. After peak ageing treatment, the main precipitation is ?' phase, the precipitation phase have obvious pinning effect to grain boundary of the alloy, it will prevent the grain growth ageing for a long-time. At the same time, strengthening role of precipitate phase make its strength increased significantly.

The finite element model, which considered the interfacial reaction layer was developed to evaluate interfacial shear strength of titanium matrix composites (TMCs) and analyze the effect of interface reaction on interfacial mechanical properties. The results show that the interfacial shear strength of SiC/Timetal-834 evaluated is about 500 MPa, and that the interfacial shear strength increases as the interfacial reaction enhances. Moreover, the relationship between the thickness of the interfacial reaction layer and the interfacial shear strength is built.