摘要
利用激光增材制造技术制备TA2/TA15梯度结构材料,研究该梯度结构材料的化学成分、显微组织和显微硬度的变化。结果表明:TA2部分宏观组织为近等轴晶组织,显微组织为魏氏α片层组织。TA15部分宏观组织是粗大的柱状晶,显微组织是细小的网篮组织。过渡区的厚度为3000μm,分成4层。随着距离TA2部分距离的增加,合金元素和β相含量逐渐增加,α相含量逐渐减少,显微组织从魏氏α片层向网篮α片层逐渐演化。固溶强化和相界面强化使得显微组织从TA2部分到TA15部分逐渐增加。
TA2/TA15 graded structural material（GSM） was fabricated by the laser additive manufacturing（LAM） process. The chemical composition, microstructure and micro-hardness of the as-deposited GSM were investigated. The results show that the TA2 part of exhibiting near-equiaxed grains was Widmanst？tten α-laths microstructure. The TA15 part containing large columnar grains was fine basket-weave microstructure. The graded zone was divided into four deposited layers with 3000 μm in thickness. As the distance from the TA2 part increases, the alloy element contents and the β phase volume fraction increase, the α phase volume fraction decreases and the microstructure shows the evolution from Widmanst？tten α-laths to basket-weave α-laths gradually. The micro-hardness increases from the TA2 part to the TA15 part due to the solid solution strengthening and grain boundary strengthening.
基金
Project(2010CB731705)supported by the National Basic Research Program of China
