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以TA15钛合金球形粉末为原料,采用激光沉积制造技术制备TA15钛合金厚壁件。通过光学显微镜(OM)、扫描电子显微镜(SEM)等方法研究了α+β两相区退火处理对TA15钛合金室温拉伸性能和显微组织的影响,并对网篮组织在拉伸过程中的变形机制进行讨论。结果表明:经α+β两相区不同温度退火后,显微组织为网篮组织或近网篮组织,退火温度对α相的形貌尺寸具有明显影响;退火后力学性能仍表现出方向上的各向异性:沉积方向上强度较低、塑性较好,而垂直沉积方向上强度高、塑性较差;粗大的层带区组织滑移变形具有“开路”作用,而柱状晶晶界对α相的滑移产生一种“固定”作用;显微硬度值随退火温度升高变化不大,显微硬度值受α相含量影响;网篮组织中的α片层组织在应力的作用下由原来近似正交方向逐渐向近似平行于应力方向变形,α片层组织的交错排列导致滑移变形时互相产生阻力;α+β两相区退火处理后的2种方向上断口形貌相似,断裂方式相同,均为韧性断裂。
TA15 Titanium alloy spherical powder as raw material, the use of laser deposition manufacturing technology TA15 titanium alloy thick-walled parts. The effects of α + β two-phase annealing treatment on the tensile properties and microstructure of TA15 titanium alloy at room temperature were studied by optical microscope (OM) and scanning electron microscopy (SEM) The deformation mechanism to discuss. The results show that the microstructures are baskets or near baskets after annealed at different temperatures in α + β two-phase region, and the annealing temperature has a significant effect on the morphology and size of α phase. The mechanical properties after annealing still show the direction Anisotropy: the deposition direction of the lower strength, good plasticity, and the vertical direction of the deposition of high strength, poor plasticity; coarse band zone tissue sliding deformation with “open circuit ” role, and the columnar grain boundaries The α-phase slip has a “fixed” effect; the microhardness value changes little with the increase of annealing temperature, and the microhardness value is affected by the alpha phase content; α-lamellar organization in the basket , The deformation of the α-sheet in the two directions of the α + β two-phase region after the annealing process is opposite to that in the stress direction. Similar appearance, the same fracture, are ductile fracture.