机械合金化对W-Ti合金组织与性能的影响

Influence of mechanical alloying on structure and properties of W-Ti alloy

以乙醇为过程控制剂,采用机械球磨方法制备W-10%Ti(质量分数)、W-10%TiH2纳米晶W-Ti粉末,晶粒粒径为30～80nm,粉体经压制后在1823K保温烧结80min得到W-Ti合金。利用X射线衍射、透射电镜和扫描电镜等手段,研究球磨时间对两种粉末及其烧结试样的相组成和微观组织的影响;测量烧结试样的密度和显微硬度。结果表明:机械合金化能够降低烧结温度,提高烧结体的密度,组织均匀且晶粒细小;利用W-TiH2球磨粉制备的W-Ti合金与W-Ti粉相比密度较高且晶粒细小。

W-Ti nanocrystalline alloying powders of 30-80 nm with composition of W-10%Ti （mass fraction） and W-30% TiH2 were prepared by mechanical milling in alcohol media. The W-Ti alloy was prepared by pressing and sintered at 1 823 K for 80 min using W-Ti powders. The phase constituent and microstructure of the powders and alloy billets were analyzed by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The density and micro-hardness of the alloy billets were also measured. The results show that mechanical alloying is helpful to decrease the sintering temperature and increase the density. The microstructure of the alloys is well-proportioned and the size of crystal is small. The alloy prepared by W-TiH2 powders has higher density than W-Ti powders, and its particle size is finer.