【作者】 赵志刚；

【导师】 邓剑如；

【作者基本信息】 湖南大学 ， 应用化学， 2002， 硕士

【摘要】 金属注射成形是一种用来制造形状复杂金属零部件的新型近净成形技术，其物料组成为金属粉末和粘结剂。粘结剂在该技术中占据核心地位，是影响金属注射成形的关键因素。粘结剂一般由低熔点组分、主体聚合物和助剂三个部分组成。当前国内粘结剂的使用还停留在经验选择的水平上，无法满足形势发展的需要。本文针对这一情况，提出了粘结剂设计的新思路，并合成理想的粘结剂体系。 首先，从金属注射成形对粘结剂的要求入手，根据结果与性能之间的关系设计合成主体聚合物。通过分析，选择甲基丙烯酸甲酯和醋酸乙烯酯为主要单体，丙烯酸丁酯和丙烯腈为辅助单体，以悬浮聚合为主要方法，制备了一系列不同组成、不同分子量的主体聚合物。对主体聚合物粘流温度的测试表明：改变主体聚合物组成和分子量可以调节粘结剂的保形性。对主体聚合物的热分析表明：甲基丙烯酸甲酯单体单元在主体聚合物中的含量达到一定范围粘结剂有很好的脱脂性能。 其次，利用高分子溶液理论和热力学相容性原理，选择了与主体聚合物相匹配的粘结剂低熔点组分。结果表明，聚乙二醇2000是合适的低熔点组分。对整个粘结剂体系的流动性研究表明：调节主体聚合物的组成和分子量，可大大改善粘结剂的流动性。对粘结剂与金属的界面参数估算表明：不同粘结剂在金属表面有不同的界面参数，只有与金属相匹配的粘结剂彼此之间才有好的粘附性能。 最后，在综合考察粘结剂保形性、流动性、粘附性和脱脂性的基础上，可以得到较为理想的粘结剂，其组成为：聚乙二醇2000为低熔点组分，聚甲基丙烯酸甲酯-醋酸乙烯酯-丙烯酸丁酯(共聚物的单体摩尔比为4：1：1，分子量为25000左右)为主体聚合物，并且PEG2000和主体聚合物的质量比为4：1。更多还原

【Abstract】 Metal injection molding is a new net shape technology applied to produce complex-shaped metal parts,in which materials are metal powder and binder. In this technique,the binder which are composed of low-melting-point component,main polymer and additives plays a key role. But it is not able to keep up with the development of metal injection molding that the binder can be obtained only in an experienced way. In order to solve the problem,this article has given a method to design new binder. And workable binder has been achieved.Firstly,according to the demand on the binder in metal injection molding and the relationship between polymers’ structure and properties,the main polymers have been designed and synthesized. On the basis of careful analysis,we have selected methyl methacrylate and vinyl acetate which acted as main monomers,butyl acrylate and acrylonitrile which acted as auxiliary monomers. With these monomers,main polymers with different composition and different molecular weight have been prepared by pearl polymerization. By testing the viscous-flowing-point of these main polymers,we have found that the bind’s shape-keeping was changed with the variety of the main polymers’ composition and molecular weight,and shape-keeping can be satisfactory when the main polymers’ composition and molecular weight are in a right position. Also,the binder’s debinding has been characteristic of thermal analysis. It results that the content of methyl methacrylate monomeric unit in the main polymers must be sufficient,otherwise,the binder could not been debinded efficiently.Secondly,according to the theory of polymeric solution and the principle of compatibility,the low-melting-point component has been choosed. It is proved that polyethylene glycol 2000 can work well with the main polymers which has beenprepared. By blending the components in a high temperature,uniform binder has been attained. We have studied the fluidity of the binder,a conclusion has been drawn that the binder can provide ideal fluidity if the main polymers’ composition and molecular have been controlled. Also,we have detected the interfacial adhesivity between the binder and the metal surface with the interfacial theory. It has been founded that excellent adhesivity came from good adaptation between the binder and the metal surface.Finally,overall analysis has been taken up on the shape-keeping,fluidity,adhesivity,and debinding. The ideal binder which can work well in many aspects has been obtained. It is that polyethylene glycol 2000 acts as the low-melting-point component,poly(methyl methacrylate-vinyl acetate-butyl acrylate) in which the monomeric unit composition should be 4:1:1 and the molecular weight should be near 25000 acts as the main polymer,and the weight fraction of the main polymers should be near twenty percent.更多还原