镧、钇对90W-Ni-Fe合金显微结构及性能的影响  

Influence of La and Y on Microstructure and Mechanical Properties of 90W-Ni-Fe Alloy

作　　者：马运柱[1] 黄伯云[1] 熊翔[1] 汪登龙[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中国稀土学报》2005年第1期85-90,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家863计划资助项目(2002AA305503)

摘　　要：以喷雾干燥 H2还原法制备的纳米级90W 7Ni 3Fe复合粉末为原料,针对不同稀土元素La,La Y,Y含量对90W Ni Fe合金性能和显微结构的影响进行了研究。结果表明:当添加La,La Y,Y在0～0.8%(质量分数)范围时,试样相对密度均在0.4%稀土时出现极大值,分别为99.3%,99.4%,99.6%。添加0.4%的La或La Y时,试样抗拉强度出现极大值,分别是906和983.5MPa,而当添加0.6%Y时,试样抗拉强度出现极大值1078MPa。添加0.2%La和Y时,试样延伸率出现极大值分别为17%和19.5%。添加La对W晶粒的抑制作用不明显,添加0.4%Y后对W晶粒长大的抑制作用较为明显,W晶粒尺寸从原来的15～20μm减少到10～15μm,W晶粒由不加稀土时的球形变为近球形或多边形,且随稀土含量的增加其影响作用更明显。La,La Y,Y同W,Ni,Fe3种元素在晶界上分别形成了W12.95Ni3.42Fe1.93La27.51,W13.61Ni2.61Fe1.07Y20.52La25.27,W13.07Ni2.96Fe1.52Y23.65(摩尔比)的中间相。添加稀土元素后,使得W在粘结相中的溶解度明显下降,由58.65%下降为添加0.4%La Y时的29.86%。当添加相同含量的稀土元素时,对合金性能影响程度的大小顺序是Y>La Y(混合稀土)>La。Nanometer 90W-7Ni-3Fe composite powder synthesized by spray drying-H_2 reduction method was used as raw materials, and influence of different content La, La-Y, Y on microstructure and mechanical properties of 90W-Ni-Fe alloy was studied. The results show that when the La, La-Y or Y content is under 0.8% (mass content), relative density of samples arrives at maximum by adding 0.4% rare earth, which is 99.3%, 99.4% and 99.6%, respectively. When 0.4% La or La-Y is added, tensile strength of samples arrives at maximum, which is 906, 983.5 MPa, respectively. But tensile strength of samples arrives at maximum when 0.6% Y is added, which is 1078 MPa. When adding 0.2% La or Y, elongation of samples arrives at maximum, which is 17%, 19.5%, respectively. Average W crystalline size decreases from 15～20 μm to 10～15 μm by adding 0.4% Y, and the W crystalline morphology is nearly spherical or polyhedral by adding some Y. The higher rare earth element content is, the more significantly influencing on W crystalline morphology is. But average W crystalline sizes are not restrained by adding La. Intermediate phase W_(12.95)Ni_(3.42)Fe_(1.93)La_(27.51), W_(13.61)Ni_(2.61)Fe_(1.07)Y_(20.52)La_(25.27), W_(13.07)Ni_(2.96)Fe_(1.52)Y_(23.65) (mol ratio) is appear at interface when La, La-Y or Y is added, respectively. Solubility of W in matrix phase decreases from 58.65% (mass content) to 29.86% when 0.4% La-Y is added. When same content of rare earth elements is added, the influence on properties of alloy is in order Y>La-Y (mixing rare earth)>La.

关 键 词：材料学 90W-Ni-Fe合金 微观结构 力学性能 稀土 

分 类 号：TF125.2[冶金工程—粉末冶金] TG146.4[冶金工程—冶金物理化学]