【摘要】 本文通过选区激光熔化成形技术(Selective laser melting, SLM)制备原位自生2%(体积分数)TiB_w/TA15钛基复合材料，探究激光功率和扫描速率对该复合材料的显微组织和室温/高温力学性能的影响规律，并揭示其强化机理。结果表明：SLM-2%TiB_w/TA15复合材料中存在孔隙缺陷，其数量随激光功率的降低和扫描速率的增大而增加。该复合材料基体由一定生长方向的原始柱状β晶和细小层片状α相组成，TiB晶须呈弥散分布；其抗拉强度随激光功率的增大而减小，随扫描速率的增大而增大，最高室温抗拉强度为1337.8 MPa，与SLM-TA15合金相比提高了15.1%;600℃抗拉强度最高值为651.1 MPa，与SLM-TA15合金相比提高了10.1%。复合材料的维氏硬度最高为403.21HV，显著高于SLM-TA15合金(345.3HV)。该复合材料强度提升的主要强化机制为载荷传递强化、热错配强化和细晶强化。更多还原

【Abstract】 In this paper, selective laser melting(SLM) was used to prepare in situ 2%TiB_w/TA15 titanium matrix composites in this work, the influences of laser power and scanning speed on the microstructure, roomtemperature and high-temperature mechanical properties were studied, and the strengthening mechanism was revealed. The results show that there exist keyholes in the 2%TiB_w/TA15, the number of which increases with the decrease of laser power and the increase of scanning speed. 2%TiB_w/TA15 is composed of the original β columnar grains and fine lamellar α phase. TiB whisker disperse. Tensile performance test shows that the tensile strength of 2%TiB_w/TA15 decreases with the increase of laser power and increases with the increase of scanning speed. The maximum tensile strength of 2%TiB_w/TA15 at room temperature is 1337.8 MPa, is 15.1% higher than that of SLMTA15 alloy. The highest 600 ℃ tensile strength is 651.1 MPa, which is 10.1% higher than SLM-TA15 alloy. The highest Vickers hardness of the composite is 403.21HV, which is significantly higher than that of SLM-TA15(345.3HV). The main strengthening mechanisms of 2%TiB_w/TA15 composite are load transfer strengthening,thermal mismatch strengthening and grain refinement strengthening.更多还原