摘要
温压是一种用加热粉末混合料与模具来提高被压制零件生坯密度的技术。加热的温度范围一般为 90～ 15 0℃。依据零件大小、粉末混合料配方及压制参数 ,与“冷”压制相比 ,采用用温压技术一般可将生坯密度提高 0 0 7～ 0 3g/cm3。可是 ,要想通过适度地提高压制温度来提高生坯密度 ,必须正确地设计粉末混合料 ,使之能在作业温度下稳定地充填阴模型腔 ,以保证压制的零件质量 (重量 )与密度均匀一致。另外 ,还必须在保持脱模力小与零件表面粗糙度值低的条件下 ,正确选择基体粉末与混入的元素粉末 ,以使生坯密度与烧结件密度都能达到最大值。要特别指出 ,润滑剂的选择是温压的关键。本文讨论了在不同的压制条件下 ,各种温压粉末混合料的性状。介绍了基体钢粉牌号和各种添加剂的数量与类型对生坯与烧结件性能的影响。着重阐述了润滑剂对生坯密度与脱模力的影响。
Warm compaction is a tech nique,which enhances the green den sity of pressed components by heat ing a powder mix and tooling to t emperatures ranging typically betw een 90 and 150℃.The gain in densit y achieved by warm pressing compar ed to'cold'compaction is typically from 0.07 to 0.30 g/cm^3 depending on the size of parts,the powder f ormulation and the compaction para meters.However,to take advantage o f this beneficial effect of a mode rate increase of the compacting te mperature on densification,powder mixes must be properly designed to provide good and stable feeding of the die cavity at the processing t emperature to allow consistent par t to part weight and density.Also, the base powder and the admixed el ements must be properly selected t o maximize both the green and sint ered densities while maintaining l ow ejection forces and good part s urface finishes.In particular,the selection of the lubricant is key in warm compaction. Tihs paper discusses the behavio r of various powder mixes warm pre ssed under different compacting co nditions.The influence of base ste el powder grade and the amount and type of various additives on the g reen and sintered properties is pr esented.Particular attention is pa id to the influence of lubricant o n green density and ejection force s.
出处
《粉末冶金工业》
CAS
2004年第1期1-9,共9页
Powder Metallurgy Industry
关键词
温压
粉末混合料
生坯性能
烧结件性能
粉末冶金
Warm Compaction
Powde r Mix
Green Compact Properties
Sinter ed Compact Properties
