铌合金中的碳化物  

Carbides in Niobium Alloy

作　　者：郑欣[1] 吕宏军[2] 李中奎[1] 王琪[2] 袁晓波[1] 付洁[1] 

机构地区：[1]西北有色金属研究院难熔金属研究所,陕西西安710016 [2]北京703所,北京100076

出　　处：《稀有金属》2006年第z2期117-120,共4页Chinese Journal of Rare Metals

基　　金：陕西省自然科学基金项目(2006E122)

摘　　要：研究了添加W,Mo,Zr和C元素的铌合金中碳化物的演化过程.以纯Nb、纯W、纯Mo、 ZrHx和C粉末为原料,按5.5%W,5.5%Mo,1.5%Zr和0.13%C的比例在'V'形混料桶中混合16～20 h,再在180 Mpa的压力下冷等静压成型,压坯在真空烧结炉中于2100～2400 ℃烧结4～5 h后,经两次电子束熔炼获得铸锭经热锻造后得到Φ13 mm的棒材,经轧制后得到板材.研究表明,烧结过程中形成了片状碳化物,用能谱和TEM分析知其为Nb2C.在电子束熔炼过程中,尽管合金中的C要挥发一部分,但由于添加的C含量较高,通过控制合理的熔炼工艺参数,在合金铸锭中仍可获得大量的碳化物Nb2C,片状的Nb2C在晶粒内均匀分布,与基体间存在明显的晶体学取向关系.热塑性加工在一定程度上改变了碳化物的分布.在最终制得的3 mm厚板材中Nb2C均匀弥散分布.经真空高温拉伸试验测试,棒材1600 ℃的σb为53 Mpa,断后延伸率δ为174.6%.Evolution of carbides in a Nb-W-Mo-Zr-C alloy was studied in the present paper.Pure Nb,pure Mo,ZrH and C powders were used as starting materials.These powders were mixed in a 'V'-shaped barrel for 16～20 h,and then cold isostatically pressed at 180 MPa.After that,the green compacts were sintered at 2100～2400 ℃ for 4～5 h.Later on,electron beam melting was adopted twice and thermal forging was followed to produce Φ13 mm rods.Finally,plates were yielded after rolling processing.Observation shows Nb2C was formed during the sintering process,which was identified with EDS and TEM.Although evaporation of C during electron beam melting,a large amount of Nb2C were achieved in the ingot by high addition of C and proper controlling of melting parameters.The distribution which Nb2C is uniform and obvious crystallographic relationship between Nb2C and Nb alloy matrix can be found.The ultimate tension strenghth of the plate is 53 MPa at 1600 ℃,and the elongation is 174.6%.

关 键 词：铌合金 碳化物 沉淀强化 

分 类 号：TG146.4+16[一般工业技术—材料科学与工程]