PEG功能化及其在粉末注射成型17-4PH不锈钢中的应用

Functionalization of PEG and Its Application in Powder Injection Molding of 17-4PH Stainless Steels

以α-甲基丙烯酸(MA)、甲基丙烯酸缩水甘油酯(GMA)、丙烯酸丁酯(BA)为单体,接枝改性聚乙二醇(PEG),得到PEG功能化产物(PEG-X),用其湿法处理17-4PH不锈钢粉末,结合聚甲醛/聚丙烯/高密度聚乙烯(POM/PP/HDPE)黏合剂制备粉末注射成型喂料,经注射、脱脂、烧结得到17-4PH烧结样品。讨论了PEG-X对17-4PH不锈钢粉末注射成型喂料和烧结样品性能的影响。结果表明:黏结剂与17-4PH不锈钢粉末的相容性被改善,两者的表面张力下降,浸润性变佳,与POM接触角从116°下降到55°,其中PEG-BA处理效果最佳;喂料流变性能、注射胚力学性能均被改善;经PEG功能化处理的粉末烧结样品晶粒细化,力学性能改善。PEG-MA处理的粉末烧结样品拉伸强度从768 MPa提高到982 MPa,PEG-GMA处理的粉末烧结样品断裂伸长率从10.25%提高到15.90%。

Theα-methacrylic acid(MA),glycidyl methacrylate(GMA),butyl acrylate(BA)were selected as monomers to graft polyethylene glycol(PEG)and forming functionalized products(PEG-X),and the 17-4PH stainless steel powder was wet deal with PEG-X.Then,the injection molding feedstock was prepared via combining 17-4PH stainless steel powder dealt by PEG-X functionalized products and polyformaldehyde/polypropylene/high density polyethylene(POM/PP/HDPE).Finally,17-4PH sintered samples were obtained by injection,degreasing and sintering.The effects of PEG-X functionalized products on 17-4PH stainless steel powder injection molding feedstock and sintered samples were discussed.The results showed that the compatibility between binder and 17-4PH stainless steel powder was improved and corresponding surface tension was decreased,then the wettability between binder and 17-4PH was improved.Finally,the 17-4PH stainless steel powder modified by PEG-BA sample presents the best compatibility,whose contact angle with POM decreased from 116°to 55°.The rheological properties of the feedstock and the mechanical properties of injected green-sample were improved simultaneously.The grain size of the sintered sample dealt with PEG-X was refined and the corresponding mechanical properties were improved.The tensile strength of the PEG-MA powder sintered sample was increased from 768 MPa to 982 MPa,and the elongation at break of the PEG-GMA powder sintered sample was increased from 10.25%to 15.90%.