Hf含量对湿化学法制备超细W-Y_(2)O_(3)复合材料显微组织与性能的影响  

Effect of Hf content on microstructure and properties of ultrafine W-Y_(2)O_(3)composites prepared by wet chemical method

作　　者：刘祯 颜硕 罗来马[1,2,3] 昝祥[1,2,3] 吴玉程[1,2,3] LIU Zhen;YAN Shuo;LUO Laima;ZAN Xiang;WU Yucheng(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology,Hefei University of Technology,Hefei 230009,China;Engineering Research Center of High Performance Copper Alloy Materials and Processing,Ministry of Education,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]合肥工业大学有色金属与加工技术国家地方联合工程研究中心,合肥230009 [3]合肥工业大学高性能铜合金材料及成形加工教育部工程研究中心,合肥230009

出　　处：《中国有色金属学报》2024年第1期125-138,共14页The Chinese Journal of Nonferrous Metals

基　　金：国家重点研发计划资助项目(2019YFE03120002);安徽省重点研发计划资助项目(202104A05020045);安徽省自然科学基金杰出青年基金资助项目(2108085J21)。

摘　　要：本文在现有W-Y_(2)O_(3)材料基础上,引入微量Hf4+掺杂入Y_(2)O_(3),调节Y_(2)O_(3)与W晶粒之间的界面关系,从而改善W基材料的综合性能。通过改变Y与Hf元素的掺杂比例,获得纳米级W基复合粉体,在氢气气氛下常规烧结制备W-Y_(2)(Hf)O_(3)复合材料。采用SEM、TEM等表征手段对W-Y_(2)(Hf)O_(3)复合材料的性能进行表征分析,研究Y与Hf元素在材料中的作用规律。结果表明:掺杂Hf元素有利于后续氢气还原,在第二相掺杂量不变条件下,当Hf含量增加时,所获得的粉体粒径减小,W-3Y-7Hf的粒径约为100 nm,明显小于传统制备的W-Y_(2)O_(3)粉体。烧结后的块体晶粒尺寸细化,显微硬度和相对密度随之增大,成分为W-3Y-7Hf烧结块体显微硬度最高,为513.7HV_(0.2),致密度为97.6%。在钨基材料中同时添加Y与Hf元素会在钨晶粒的晶界与晶内处形成复合第二相氧化物Y_(2)Hf_(2)O_(7)颗粒,尺寸更小,弥散强化作用更强;其中,W-3Y-7Hf中第二相氧化物颗粒尺寸仅为200 nm左右,与钨晶界产生良好的界面结合关系,形成半共格界面。In this paper,based on existing W-Y_(2)O_(3)materials,trace amounts of Hf4+were introduced into Y_(2)O_(3)to regulate the interface between the second phase yttrium oxide and tungsten grains,and thus improving the overall performance of tungsten-based materials.By adjusting the doping ratio of Y to Hf elements,nanoscale tungsten-based composite powders were obtained and W-Y_(2)(Hf)O_(3)composites were prepared by conventional sintering with hydrogen.The W-Y_(2)(Hf)O_(3)composites were characterized and analyzed by SEM and TEM to study the action law of Y and Hf elements in the material.The results show that the doping of Hf elements is beneficial to the subsequent hydrogen reduction.Under the condition of constant second phase doping,when the Hf content increases,the particle size of the obtained powder decreases,and the particle size of W-3Y-7Hf is about 100nm,which is obviously smaller than the traditional prepared W-Y_(2)O_(3)powder.After sintering,the grain size of the sintered block is refined,and the microhardness and relative density increase.The sintered block with W-3Y-7Hf has the highest microhardness,which is 513.7HV_(0.2),and the density is 97.6%.The addition of both Y and Hf elements to the tungsten-based material results in the formation of composite second-phase oxide Y_(2)Hf_(2)O_(7)particles at the grain boundaries and intra-grain of the tungsten grains,which are smaller in size and have a stronger dispersion strengthening effect.The particle size of the second phase oxide in W-3Y-7Hf is only about 200 nm,which has a good interfacial bonding relationship with tungsten grain boundaries and forms a semi-coherent interface.

关 键 词：纳米级钨基复合粉体 湿化学法 弥散强化 复合第二相氧化物 

分 类 号：TB33[一般工业技术—材料科学与工程]