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

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-YV-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...

Microstructure and Flame-resistant Properties of Ti-xV-15Cr (x = 20,25,30,35) Alloys by Laser Solid Forming

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.