烧结工艺对含W-25% Cu超细粉末金刚石工具胎体力学性能的影响

将超细W-25%(质量分数,下同)Cu粉末应用到金刚石工具胎体中。借助SEM形貌、金相显微观察、抗弯和冲击试验等分析手段,研究了烧结工艺参数对添加超细W-25%Cu粉胎体的力学性能的影响;并利用极差分析方法确定影响因素的敏感性,从大到小依次排列为烧结温度、保温时间、保压压力。

Microwave Sintering of W-15Cu Ultrafine Composite Powder Prepared by Spray Drying & Calcining-continuous Reduction Technology

The effects of microwave sintering and conventional H2 sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying ＆ calcining-continuous reduction technology were investigated. In comparison to the conventional HE sintering processing, microwave sintering to W-15Cu can be achieved at lower sintering temperature and shorter sintering time. Furthermore, higher performances in microwave sintered compacts were obtained, but high microwave sintering temperature or long microwave sintering time could result in coarser microstructures.

Effects of Activated Sintering Process on Properties and Microstructure of W-15Cu Alloy

The effects of activated sintering technology of H2 atmosphere sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying calcining-continuous reduction technology were investigated.The experimental results showed that W-15Cu alloy,consolidated by activated sintering technology of H2 atmosphere sintering for 1 h at 1300 ℃,with 98.5 % relative density,transverse rupture strength 1218 MPa,Vickers hardness HV0.5 378,average grain size about 1.2 μm and thermal conductivity 192 W/m·K,was obtained.In comparison to the normal sintering process,activated sintering process to W-15Cu alloy could be achieved at lower sintering temperature.Furthermore,better properties in activated sintered compacts were obtained,and activated sintering process resulted in finer microstructure and excellent properties.

光伏电力开关用W-25Cu复合材料的微观组织和抗电弧侵蚀性研究

通过水热-共还原法制备细晶W-25Cu复合材料,并分析其微观组织和电弧侵蚀后组织形态的变化。结果表明:W-25Cu复合材料的显微组织具有明显的全致密化特点,Cu相将细小W颗粒全部包围,Cu相与W相的分布状态非常均匀,W相的晶粒尺寸为1~3μm,断口区域表现出明显的韧窝断裂特征,断裂阶段还生成了众多弯曲的细密撕裂棱,形成了许多稠密的细小断口韧窝。经电弧侵蚀后,表面物相构成以Cu、W两相为主,表面形貌较为平整,未出现明显的孔洞与裂纹结构。在断裂闭合阶段,材料转移过程基本表现为电弧转移、熔桥转移及喷溅蒸发这几种类型。

共还原工艺对W-25Cu纳米复合粉体及其挤压组织与性能的影响

以钨酸钠（Na2WO4·2H2O）和硝酸铜（Cu（NO3）2·3H2O）为原料,采用水热-共还原工艺制备W-25Cu纳米复合粉末,包套热挤压工艺制备细晶W-25Cu合金。利用X射线衍射仪（XRD）、扫描电镜（SEM）和透射电镜（TEM）等分析测试手段研究了共还原工艺对W-25Cu复合粉体及其挤压组织与性能的影响。研究结果表明：相比于一段还原工艺,两段还原过程中先还原出的Cu相能够通过增加异相形核细化晶粒,对后续W相的还原具有催化与细化作用。两段还原得到的W-Cu复合粉体微观组织呈典型的钨包铜结构,粒度达到纳米级,分散性良好。烧结热挤压后,制备的合金具有细密组织与良好性能,致密度达到99.52%,硬度提高到HB 272,导电率提高到52.8%IACS,抗拉强度达到282 MPa。