增塑挤压成形钨基合金棒材溶剂-热二步脱脂工艺研究

大长径比钨基合金棒材制备的关键是成形、脱脂和后续的烧结控制.基于增塑挤压成形的研究,对Ф24 mm钨基合金挤压棒坯的快速无缺陷脱脂,即溶剂-热二步脱脂工艺进行了研究.结果表明:在溶剂脱脂温度为45℃,脱脂12 h后,Ф24 mm钨基合金棒材一次脱脂率达45%;在溶剂脱指过程中增加干燥阶段,脱脂率可达70%以上;在真空气氛下对脱脂棒材进行后续热脱脂,坯体保形性好,且在12 h内,脱脂可以全部完成.采用溶剂-热二步脱脂工艺可以实现Ф24 mm钨基合金挤压棒材的快速无缺陷脱脂.

Study on solvent-thermal two-step degreasing process of tungsten-based alloy rods by plasticizing extrusion molding

The keys of preparation of large aspect ratio tungsten-based alloy rods are forming,degreasing and subsequent sintering control.According to the research of powder extrusion molding(PEM),the fast and defect-free degreasing of Ф24 mm tungsten-based alloy rods,made by two-step degreasing process including solvent and thermal stages,were mainly investigated in this paper.The results showed that,the binder removal ratio was about 45 wt.% of Ф24 mm tungsten-based alloy rods when the solvent degreasing temperature was 45 ℃ and the holding time was 12 h.The binder removal ratio was above 70 wt.% by increasing the drying stage during solvent degreasing.The green maintained good shape during subsequent thermal degreasing in a vacuum atmosphere,and the binder removal completed within 12 h.The solvent-thermal two-step degreasing process could achieve a fast and defect-free degreasing of Ф24 mm tungsten-based alloy rods extruded.