热处理制度对SLM成形TA15钛合金组织及性能的影响

Effect of heat treatment on microstructure and properties of TA15 titanium alloy formed by SLM

实验采用选区激光熔化成形(SLM)技术制备了TA15钛合金试样,研究了热处理制度对TA15钛合金试样微观组织和拉伸及冲击性能的影响。研究结果表明,单重热处理方式下,随保温时间的延长和退火温度的升高,微观组织α’马氏体逐渐分解,次生α相和β相的体积分数则逐渐增加,试样拉伸强度整体呈下降趋势,但断裂韧性呈现先升高后降低的趋势。其中在850℃保温4 h热处理制度下,试样具有较优的综合性能,其抗拉强度为1033 MPa,冲击功为38 J。双重热处理制度下,显微组织主要是以网篮状为主的α+β两相组织,微观组织均质化程度更高,表现为宏观性能分散性较小,其抗拉强度均值达1029 MPa,冲击功为40 J。

TA15 titanium alloy samples were prepared by selective laser melting(SLM)forming technology.The effects of heat treatment on microstructure,tensile and impact properties of TA15 titanium alloy samples were studied.The results show that under the single heat treatment mode,with the prolongation of holding time and the increase of annealing temperature,a'martensite in the microstructure gradually decomposes,and the volume fraction of the secondaryαphase andβphase gradually increases,and the tensile strength of the samples show a downward trend,but the fracture toughness increases at first and decreases subsequently.Under the heat treatment system of 850℃for 4 h,the sample has better comprehensive properties,its tensile strength is 1033 MPa,and the impact energy is 38 J.Under the double heat treatment mode,the microstructure is mainly a basket-weave structureα+βtwophase structure,the degree of microstructure homogenization is higher,which shows that the dispersion of macroscopic properties is smaller,with an average tensile strength of 1029 MPa and impact energy of 40 J.