碳化物对铌基多相合金力学性能和组织结构的影响  

Effect of Carbide Additions on the Mechanical Properties and Microstructure of Nb-based Multiphase Alloy

作　　者：魏文庆[1] 魏尊杰[2] 张淑芝[1] 刘炳强[1] 崔大伟[1] 

机构地区：[1]潍坊学院,山东潍坊261061 [2]哈尔滨工业大学,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2015年第4期901-907,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助(51004077)

摘　　要：采用纳米压痕和原子力显微镜对Nb-21Ti-4C-x Al(x:0,5,10,15 at%,下同)、Nb-35Ti-4C及Nb-25Ti-8C合金Nbss、(Nb,Ti)C、Nb3Al及相界面的力学性能和变形行为进行了研究。研究表明:Ti、Al元素合金化能有效提高Nbss的硬度,且Al强化效果优于Ti;高硬度的碳化物、Nb3Al与Nbss界面结合良好是理想的增强相。热处理后(Nb,Ti)C内部析出二次Nbss,改善了碳化物的变形行为,提高了韧性;热处理后Nbss内部组织均匀化及位错密度降低导致Nbss硬度下降。Ti、Al、C原子含量变化及热处理对Nbss的弹性模量影响不大。The mechanical properties and deformation behaviors of Nbss, （Nb, Ti）C, Nb3A1 and the interface for as cast and heat treated Nb-21Ti-4C-xAI （x=0, 5, 10, 15 at%）, Nb-35Ti-4C and Nb-25Ti-8C alloys were investigated using nanoindentation and atomic force microscopy （AFM）. The results show that Ti and A1 can effectively improve the hardness of Nbss and the capacity of solid solution strengthening of A1 is better than that of Ti. The hard carbide and Nh3A1 which has a strong bonding with Nbss matrix can enhance the alloy before and after heat treatment. The eutectoid transformation of the large-sized carbide after heat treatment leads to less possibility for the forming of cracks on the carbide surface, which in turn improves the toughness. After heat treatment, the hardness of Nbss matrix decreases due to the homogenization of matrix microstructure and the decrease in the dislocation density. However, the deviations of the elastic modulus are unconspieuous with the change of the Ti, A1, C fraction and heat treatment for all alloys.

关 键 词：纳米压痕 力学性能 Nb-Ti-Al合金 碳化物 

分 类 号：TG146.416[一般工业技术—材料科学与工程]