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通过碳热还原法制备了多孔氮化钛预制体,利用挤压铸造法制备双连续氮化钛增强铝基复合材料,并研究了铝合金含量对复合材料显微组织和力学性能的影响,以及复合材料的强韧化机制。结果表明:随着复合材料铝合金含量的增加,复合材料的弯曲强度和显微硬度下降,断裂韧性增加。复合材料的断裂模式为氮化钛等轴晶粒沿晶韧性断裂。氮化钛与铝合金不发生化学反应,避免了过度的界面反应对复合材料力学性能的不利影响。复合材料强韧化机制主要有负荷传递、位错增殖和裂纹偏转。
The porous TiN preform was prepared by carbothermal reduction method. The dual continuous titanium nitride reinforced aluminum matrix composites were prepared by squeeze casting. The effects of aluminum alloy content on the microstructure and mechanical properties of the composites were also studied. Toughening mechanism of composite materials. The results show that the flexural strength and microhardness of the composites decrease and the fracture toughness increases with the increase of the content of the composite aluminum alloy. The fracture mode of the composites is the fracture of the intergranular TiN grains along the ductile toughness. Titanium nitride and aluminum alloy chemical reaction does not prevent excessive interface reaction on the mechanical properties of the composite adverse effects. The toughening mechanism of composites mainly includes load transfer, dislocation propagation and crack deflection.