Effect of Die Wall Lubrication on Warm Compaction Powder Metallurgy

查看全文 作　　者：LI Yuan-yuan, NGAI Tungwai Leo, ZHANG Da-tong, LONG Yan, XIA Wei (College of Mechanical Engineering, South China University of Technology, Guangzhou 510640, China) 出　　处：《厦门大学学报(自然科学版)》索引2002年第41卷第S1期,共2页 基　　金：ProjectsupportedbyNationalNaturalScienceFoundationofChina (KeyProject 5 0 1 3 5 0 2 0 ) ;NationalAdvancedTechnologyResearchandDevelopmentProject (863Project 2 0 0 1AA3 3 70 1 0 ) ;MinistryofEducation (Excellentpersonnelfor 2 1 stCenturyTrainingProject[2 摘　　要：Die wall lubrication was applied on warm compaction powder metallurgy in hope to reduce the concentration level of the admixed lubricant since lubricant is harmful to the mechanical property of the sintered materials. Iron-based samples were prepared by die wall lubricated warm compaction at 135 ℃ and 175 ℃, using polytetrafluoroethylene (PTFE) emulsion as die wall lubricant. A compacting pressure of 700 MPa and 550 MPa were used. The admixed lubricant concentration ranging from 0 to 0.6 wt.% was used in this study. Compared with non-die wall lubricated samples, the die wall lubricated samples have higher green densities. Results show that in addition to the decrease in ejection forces, green density of the compacts increased linearly with the decrease in admixed lubricant content. Mechanical property of the sintered compacts increase sharply when the admixed lubricant concentration reduced to 0.125 wt.% or less. Ejection force data indicated that samples with die wall lubrication show lower ejection forces when compared with samples without die wall lubrication. No scoring was observed in all experiments even for samples contain no admixed lubricant. Our results indicated that under experimental condition used in this study, no matter at which compaction pressure, compaction temperature, graphite and lubricant contents in the powder the die wall lubricated warm compaction would give the highest green density and lowest ejection force. It can be concluded that combination of die wall lubrication and warm compaction can provide P/M products with higher density and better quality. It is a feasible way to produce high performance P/M parts if suitable die wall lubrication system was applied. 关 键 词：warm compaction die wall lubrication powder metallurgy