摘要
目的针对316L不锈钢注射成形,研究一种环境友好型的水溶性黏结剂,并探究水脱脂温度对PEG脱除率的影响。方法配置不同PEG/PMMA比例的黏结剂,通过成形后的形貌及SEM确定黏结剂的比例,对成形完整的生坯进行流变性能测试,最后将生坯放入水浴锅中脱脂,通过SEM观察形貌。结果通过注射成形得出76%(质量分数,下同)PEG、79%PEG和82%PEG 3种喂料能够注出完整的生坯,同时根据SEM观察发现316L不锈钢粉末被黏结剂均匀包裹。在160℃、剪切速率102~105s-1条件下,3种喂料黏度均低于1000Pa·s,符合注射成形的要求。在生坯脱脂过程中,PEG脱除率随着脱脂温度的升高而升高。PEG的脱除使生坯内部形成大量孔隙,有利于后续热脱脂与预烧结的进行。结论与其他成分相比,成分为79%PEG+19%PMMA+5%SA的黏结剂喂料具有较好的流动性,适合注射成形,成形出的生坯形貌完整,内部孔洞较少,并且经过脱脂后仍能保持原始形状,无外部缺陷。生坯在60℃水温下脱脂,PEG脱除率最大,经过10h脱脂后PEG脱除率达到80%。
The work aims to develop an environmentally friendly water-based binder for the injection molding of 316L stainless steel,and explore the effect of water degreasing temperature on the removal rate of PEG.Different ratios of PEG/PMMA binders were prepared,and the appropriate binder ratio was determined by observing the morphology and SEM of the molded samples.The rheological properties of the complete molded green parts were tested.Finally,the green parts were degreased in a water bath,and their morphology was examined with SEM.Three types of feedstock with PEG contents of 76wt.%,79wt.%,and 82wt.%were successfully molded into complete green parts by injection.According to SEM observations,the 316L stainless steel powder was not covered evenly by the binders.At 160℃,the viscosity of all three binders was below 1000 Pa·s,and the shear rate ranged from 102 to 105 s-1,meeting the requirements for injection molding.The removal rate of PEG from the green parts increased with the degreasing temperature.The removal of PEG resulted in the formation of numerous pores inside the green parts,which proved beneficial for subsequent debinding and presintering processes.The binder with a composition of 79wt.%PEG+19wt.%PMMA+5wt.%SA exhibits better fluidity in feeding compared with other compositions,making it suitable for injection molding.The resulting molded green parts have a complete morphology with fewer internal voids,and they retain their original shape without any external defects after degreasing.Degreasing the green parts at a water temperature of 60℃achieves the highest removal rate of PEG,with the PEG removal rate reaching 80%after 10 hours of de-greasing.
作者
李传勇
张韦晨
李璐
苑振涛
王枭
MUHAMMAD Dilawer Hayat
陈刚
LI Chuan-yong;ZHANG Wei-chen;LI Lu;YUAN Zhen-tao;WANG Xiao;MUHAMMAD Dilawer Hayat;CHEN Gang(Faculty of Material Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;Research Center for Analysis and Measurement,Kunming University of Science and Technology,Kunming 650093,China;City College,Kunming University of Science and Technology,Kun-ming 650051,China;Faculty of Engineering,University of Waikato,Hamilton 3240,New Zealand;Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China)
出处
《精密成形工程》
北大核心
2023年第12期150-156,共7页
Journal of Netshape Forming Engineering
基金
云南省重点研发项目-国际科技合作项目(202103AF140004)
中央引导地方科技发展资金(202207AB110003)
云南省重点研发项目(202203AM140010)。
