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.
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 de- fect-free degreasing of Ф24 mm tungsten-based alloy rods, made by two-step degreasing process including sol- vent and thermal stages ,were mainly investigated in this paper. The results showed that, the binder removal ra- tio was about 45 wt. % of ~24 mm tungsten-based alloy rods when the solvent degreasing temperature was 45 ~C 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.
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