【作者】 李政；

【导师】 徐卫兵；

【作者基本信息】 合肥工业大学 ， 材料工程（专业学位）， 2018， 硕士

【摘要】 金属粉末注射成型是一种新型的粉末冶金净成型技术,粘结剂是金属粉末注射成型喂料的关键成分,粘结剂与金属粉末之间的相互作用对喂料的均一性、流动性、成型体的保型性、粉末装载量和脱脂烧结后样品性能等具有重要影响。本文研究官能化的聚丙烯酸酯粘结剂,具体内容如下:分析了 17-4PH金属粉末表面可能存在的基团,设计并合成了以甲基丙烯酸甲酯和丙烯酸丁酯为主体,甲基丙烯酸缩水甘油酯、甲基丙烯酸羟乙酯、甲基丙烯酸为不同功能单体的不同分子量的官能化聚丙烯酸酯粘结剂。优化了官能化聚丙烯酸酯粘结剂的骨架配比、官能团的摩尔量以及粘结剂的熔体粘度,得到最优的官能化聚丙烯酸酯粘结剂。研究了官能化聚丙烯酸酯粘结剂与金属粉末之间的相互作用对喂料的流动性、坯体保型性、粉末装载量和脱脂烧结后样品性能的影响。发现:在相同粉末装载量下,喂料的流动性随着粘结剂与金属粉末之间相互作用的增强而增大。流变指数n和粘流活化能E也是如此。羟基官能化的粘结剂的流动性最好,相对于参比粘结剂,综合流变指数是参比的1.5倍。在不同的粉末装载量下,随着粘结剂与金属粉末之间相互作用的增强,喂料的临界粉末装载量得到提高。羟基官能化的粘结剂临界粉末装载量为56vol.%-58vol.%,相对于参比粘结剂,提高了 2vol.%。注射成型的样品进行相关的性能测试,结果表明,随着粘结剂与金属粉末之间相互作用的增强,样品的体积收缩率减小,孔隙率减小,相对密度提高,弯曲强度增大,脱脂率减小。更多还原

【Abstract】 Metal powder injection molding is a new net technology of powder metallurgy.The binder is the key component for the feedstock of metal powder injection molding.The interaction between the binder and the metal powder has a significant influence on the homogeneity,fluidity,molded shape retention,powder loading and properties of the sample after degreasing and sintering.The functionalized polyacrylate binders were studied in this article.The main contents were summarized as follows:By analyzing the possible groups on the surface of 17-4PH metal powder,the functionalized polyacrylate binders of different molecular weights was designed and synthesized.Methyl methacrylate and butyl acrylate were designed as backbone.Glycidyl methacrylate,hydroxyethyl methacrylate and methacrylate were designed as functional monomers.Skeleton ratio,the amount of functional groups and the melt viscosity were optimized to obtain the optimal formula for the functionalized polyacrylate binder.The effect of the interaction between the functionalized polyacrylate binder and the metal powder on the fluidity of the feedstock,the shape retention of the green body,the powder loading and the properties of the sample after degreasing and sintering were investigated.It was found that the fluidity of the feedstock increased with the interaction between the binder and the metal powder increasing at the same powder loading.The same is true of the rheological index n and the viscous flow activation energy E.The hydroxyl-functionalized binder had the best fluidity and the composite rheological index was 1.5 times the reference binder.At the different powder loadings,the critical powder loading of the feedstock increased with the interaction between binder and metal powder increasing.The hydroxyl-functionalized binder had a critical powder loading of 56 vol.%to 58 vol.%,an increasing of 2 vol.%over the reference binder.The properties of the samples after degreasing and sintering were tested.The results showed that with the increasing of the interaction between the binder and the metal powder,the volume shrinkage of the samples decreased,the porosity decreased,the relative density increased,the bending strength increased,and the degreasing rate decreased.更多还原