TiB_(2)/AlSi10Mg选区激光熔化成形组织与性能

Microstructure and Properties of TiB_(2)/AlSi10Mg Composite Prepared by Selective Laser Melting

采用选区激光熔化成形技术(SLM)制备AlSi10Mg合金和TiB_(2)/AlSi10Mg复合材料,利用XRD、SEM、TEM、万能拉伸实验机和维氏硬度计等对TiB_(2)/AlSi10Mg复合材料的力学性能、组织结构等进行了表征分析。结果表明:AlSi10Mg合金中加入增强相TiB_(2)后,其SLM成形件的致密度、屈服强度和断裂强度分别由96.8%、156.3 MPa和366.3 MPa增加至99.4%、170.1 MPa和413.4 MPa。TiB_(2)/AlSi10Mg成形件屈服强度的提升主要来源于Orowan强化、弥散强化和细晶强化。与此同时,TiB_(2)增强相的添加使得裂纹源增加,大幅度降低了AlSi10Mg合金的塑性(从8.5%下降到4.2%),其断裂机制由准解理断裂转变为解理断裂。

AlSi10Mg alloy and TiB_(2)/AlSi10Mg composite alloy were prepared by selective laser melting(SLM),and then the microstructure and mechanical properties were characterized and analyzed by X-ray diffraction(XRD),SEM,TEM,tensile test machine and Vickers hardness tester.The results indicate that once the TiB_(2) particles added into AlSi10Mg,density,yield strength and fracture strength of the SLM AlSi10Mg alloy were improved from 96.8%,156.3 MPa and 366.3 MPa to 99.4%,170.1 MPa and 413 MPa,respectively.The raise of yield strength of TiB_(2)/AlSi10Mg is the result of Orowan strengthening,dispersion strengthening and fine grain strengthening.Moreover,crack source increases with the addition of TiB_(2),and the plasticity reduces from 8.5%to 4.2%.The fracture mechanism changes from quasi-cleavage fracture to cleavage fracture.