直接能量沉积Ti-XV-15Cr(X=20,25,30,35)合金的组织和阻燃性能  

Microstructure and Flame-Resistant Properties of Ti-XV-15Cr(X=20,25,30,35) Alloys Prepared by Directed Energy Deposition

作　　者：张凤英[1] 王刚 刘桐[1] 王坤[1] 康晨诺 彭艺杰 李尧 谭华[2] 陈永楠[1] Zhang Fengying;Wang Gang;Liu Tong;Wang Kun;Kang Chennuo;Peng Yijie;Li Yao;Tan Hua;Chen Yongnan(School of Materials Science and Engineering,Chang’an University,Xi’an 710064,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]长安大学材料科学与工程学院,陕西西安710064 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2021年第2期380-388,共9页Rare Metal Materials and Engineering

基　　金：National Key Research and Development Program of China (2016YFB1100103);Natural Science Basic Research Plan in Shaanxi Province of China (2020JM-239);Fundamental Research Funds for the Central Universities CHD (300102319208, 300102310501);National Training Program of Innovation and Entrepreneurship for Undergraduates (S202010710142)。

摘　　要：使用直接能量沉积技术,以纯Ti、纯V和纯Cr粉末为原料制备一系列Ti-XV-15Cr(X=20,25,30,35)合金。研究了V含量对Ti-XV-15Cr合金的晶粒形貌、显微硬度、弹性模量及阻燃性能的影响。结果表明,Ti-20V-15Cr、Ti-25V-15Cr和Ti-30V-15Cr合金的显微组织由外延生长的柱状晶和顶部细小的等轴晶组成,随着V含量的增加,柱状晶粒的长/宽比逐渐减小。而Ti-35V-15Cr合金的显微组织与Ti-20V-15Cr,Ti-25V-15Cr和Ti-30V-15Cr有很大的不同,除了顶部是细小的等轴晶,几乎全由近等轴晶组成。结合柱状晶向等轴晶转变(CET)模型以及柱状晶层的高度与Z轴抬升量(ΔZ)之间的关系,解释了微观组织的形成机理。Ti-XV-15Cr合金的平均显微硬度随V含量的增加而略有增加,其弹性模量在123.8与137.6 GPa之间。阻燃测试表明,Ti-35V-15Cr合金具有最佳的阻燃性能。A series of Ti-XV-15 Cr(X=20, 25, 30, 35, wt%) alloys were prepared by directed energy deposition(DED) technique, where pure Ti, pure V, and pure Cr powders were used as raw materials. The effects of V content on grain morphology, microhardness, elastic modulus and the flame-resistant properties of Ti-XV-15 Cr alloys were investigated. It is found that the microstructures of Ti-20 V-15 Cr, Ti-25 V-15 Cr and Ti-30 V-15 Cr alloys are composed of columnar grains growing epitaxially and fine equiaxed grains at the top region, and the aspect ratio of the columnar grains decreases gradually with increasing the V content. The microstructure of Ti-35 V-15 Cr alloy is composed of near-equiaxed grains except at the very top region, which is very different from the microstructure of Ti-20 V-15 Cr, Ti-25 V-15 Cr and Ti-30 V-15 Cr alloys. The formation mechanism of microstructure is explained by combining the columnar to equiaxed transition(CET) model and the relationship between the height of the columnar grains layer and Z axis increment(ΔZ). The average microhardness of Ti-XV-15 Cr alloys increases slightly with increasing the V content, and the elastic modulus is between 123.8 and 137.6 GPa. Flame-resistant test shows that Ti-35 V-15 Cr alloy exhibits the best flame-resistant properties.

关 键 词：Ti-V-Cr合金 显微组织 直接能量沉积 阻燃性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]