Microstructure and mechanical properties of Al-TiB_2/TiC in situ composites improved via hot rolling

高温轧制Al-TiB_2/TiC原位复合材料的显微组织及力学性能（英文）

A kind of Al-TiB2/TiC in situ composite with a homogenous microstructure was successfully prepared through in situ reaction of pure Ti and Al-B-C alloy with molten aluminum.In order to improve the distribution of the particles and mechanical properties of the composites,subsequent hot rolling with increasing reduction was carried out.The microstructure evolution of the composites was characterized using field emission scanning electron microscopy(FESEM)and the mechanical properties were studied through tensile tests and microhardness measurement.It is found that both the microstructure uniformity and mechanical properties of the composites are significantly improved with increasing rolling reduction.The ultimate tensile strength and microhardness of the composites with90%rolling reduction reach185.9MPa and HV59.8,respectively,140%and35%higher than those of as-cast ones.Furthermore,the strengthening mechanism of the composite was analyzed based on the fracture morphologies.

在铝熔体中利用纯Ti与Al-B-C合金的原位反应成功制备出一种原位自生颗粒增强的Al-TiB_2/TiC复合材料,随后采用高温轧制改善其增强颗粒在基体中的分布与复合材料的力学性能。利用场发射扫描电镜表征复合材料在轧制变形过程中的显微组织演变过程,并通过拉伸和显微硬度试验测定复合材料的力学性能变化。结果表明:随着轧制压下量的增加,复合材料的显微组织得到明显改善,颗粒分布更加均匀;当压下量达到90%时,复合材料的抗拉强度提高到185.9 MPa,显微硬度达到HV 59.8,与铸态样品相比分别提高了140%和35%。另外,基于拉伸样品的断口形貌分析了复合材料的强化机理。