选区激光熔化TiC/AlMgSc复合材料组织与性能研究

Microstructure and properties of TiC/AlMgSc composites by selective laser melting

摘要:

采用选区激光熔化成形技术制备了TiC/AlMgSc铝基复合材料，通过X射线衍射仪、扫描电镜以及万能试验机系统地分析了铝基复合材料相组成、微观形貌、再结晶分布以及力学性能，并理论计算了位错密度和TiC增强相对合金强度的提升值。结果表明：TiC增强颗粒的添加使得TiC/AlMgSc复合材料内部位错密度增加了105%，达到了0.72×1014 m-2；＜1 μm晶粒和亚晶界比例显著增加，再结晶程度降低；抗拉强度、屈服强度和延伸率分别达到611 MPa、589 MPa、11.0%，相比AlMgSc合金屈服强度提升了70 MPa，延伸率下降了1.1%。

Abstract:

TiC/AlMgSc aluminum matrix composites were fabricated by selective laser melting. The phase composition, microstructure, recrystallization distribution and mechanical properties of aluminum matrix composites were systematically analyzed by X-ray diffraction, scanning electron microscope and universal testing tensile machine. The increase of dislocation density and TiC strength relative to alloy strength was calculated theoretically. The results show that the dislocation density of TiC/AlMgSc composites increases by 105% to 0.72×1014 m-2 with the addition of TiC reinforced particles, the proportion of <1 μm grains and sub-grain boundaries increased significantly, and the degree of recrystallization decreases. The tensile strength, yield strength and elongation reached 611 MPa, 589 MPa and 11.0%.Compared with AlMgSc alloy, the yield strength increased by 70 MPa and the elongation decreased by 1.1%.