Preparation And Properties Of Fiber Reinforced Ti/Al₃Ti Laminate Composites

Fiber reinforced metal matrix composites have gradually become the hot topic researchers study. This kind of composites mainly enhances the strength and toughness by introducing fibers, but the studies with respect to fiber reinforced laminated composites are rarely reported. In the experiment, the fiber reinforced laminate composite Ti/Al3Ti was successfully fabricated via vacuum hot pressing method. Owing to the high strength, high modulus, good corrosion resistance and thermostability of fiber introduced intothe matrix Al3Ti, the overall strength of the material is improved obviously as well as toughness, such that this class of fibers reinforced laminated composite can be employed in military equipment, aerospace and automotive engineering. In this thesis, the fabrication process and mechanical properties of metal-intermetallic laminated composites reinforced by W fiber and C fiber respectvely are both investigated. The experimental demonstracted that:During the process of fabricating W fiber reinforced Ti/Al3Ti laminate composite, it was found that when preserved at the maximum temperature for 4h and applied 3 MPa pressure followed by cooling down with the furnace, the residual W maintained to a relatively large degree and the cracks and defects decreased compared to other fabrication parameters. As is known that peritectic reaction of distinct mechanisms can occur between W fiber and Al because of the difference in temperature, but this fabrication process does not create no existence of W-Al compound. W and A1 finally become solid solution.During the process of fabricating Carbon fiber reinforced Ti/Al3Ti laminated composite,the wettability of fiber and matrix were improved after coating copper on the surface of carbon fiber. The copper coating effect is optimized when the plating temperature is 30℃ and theoscillating time is 40 min. It was observed that when keeping time for 1.5h at the maximum temperature for 1.5h and keeping the pressure for 3MPa and then cooled down with the furnace, the C fiber reinforced laminated composite shows no conspicuous defects in microstructure, which includes phases of C, Ti and Al3Ti. The quasi-staticcompression test showed that when the loading orientations are perpendicular and parallel to the layers, the compression strengthsof the laminated composite are 1545MPa and 1175MPa, respectively.Under the condition of high strain rate loading, it is obtained that the dynamic compression strength of C fiber reinforced laminate composite is 1724MPa when the loading is perpendicular to the layers. Otherwise, the pulling out of fiber was observed in both quasi-static and dynamic compression tests. In the tensile tests, the tensile strength of carbon fiber enhancedthe Ti/Al3Ti laminate composites was 500MPa, the strain to failue was 0.13,and the tensile strength of the Ti/Al3Ti laminate composite was 413MPa and strain to failue was 0.11. The tensile strength and plasticity of materials and plastic of materials were improved laminate composite were improved due to the contribution of the carbon fiber.