90W-7Ni-3Fe高比重合金薄板材的流延法制备

Preparation of 90W-7Ni-3Fe Heavy Alloy Sheet by Tape-casting

采用流延成型工艺,通过排胶、烧结得到90W-7Ni-3Fe合金板坯,通过冷轧工艺得到厚度小于0.1mm的90W-7Ni-3Fe薄板材。通过扫描电子显微镜观察实验制得的素坯,混合金属颗粒均匀地分布在粘结剂中。对制得的流延素坯进行综合热分析,制定90W-7Ni-3Fe流延素坯的排胶方案。通过碳硫分析仪测得排胶烧结后的90W-7Ni-3Fe合金板坯残碳量(质量分数)为0.012%~0.018%。对不同烧结温度的90W-7Ni-3Fe板坯的组织形貌、相对密度及硬度分析,烧结温度在1450℃时,致密化程度提高,W颗粒相未过大生长,板型保持较好。对烧结后的90W-7Ni-3Fe板坯进行冷轧处理,W颗粒沿轧制方向被拉长成扁椭球状,Ni-Fe相由于塑性比W颗粒好也被沿轧制方向挤压,消除了部分气孔,有效地提高了板坯的致密度及硬度。

90W-7Ni-3Fe heavy alloy thin plate, with the thickness less than 0.1 mm, was prepared by the process of tape-casting, laminating, rubber discharging, sintering and cold rolling. Scanning electron microscope was used to observe the tapes. The mixed metal particles are evenly distributed in the binder. Comprehensive thermal analysis was carried out to get the binder remove scheme. The results of the carbon/sulfur analysis show that the binder in W-Ni-Fe alloy is almost removed, and the carbon content is 0.012%~0.018%. The morphology, relative density and hardness of 90 W-7 Ni-3 Fe plates with different sintering temperatures were analyzed. When the sintering temperature is 1450 ℃, the degree of densification increases and the grain size of W does not grow too large. The sintered 90 W-7 Ni-3 Fe plates were treated by cold rolling. The W grains are elongated into the oblate ellipsoidal shape along the rolling direction, while the Ni-Fe phase which has better toughness than W grains is also stretched and lengthened in the rolling direction, and pores are eliminated, improving the density and hardness of the plate effectively.