Al2O3-SiCw-SiCnp复合陶瓷刀具材料粉体的分散混合工艺研究

2019-08-30

作者：刘雪飞1，2，3，刘含莲1，2，，黄传真1，2，王利梅1，2，姚鹏1，2，刘璐1，2 单位：1山东大学；2高效洁净机械制造教育部重点部重点实验室；3山东大学国家级机械基础实验教学示范中心

摘要：一维材料SiC晶须（SiCw）具有高弹性模量和高抗拉强度等优良特性，常用作陶瓷刀具材料的增韧补强相，但极易产生缠绕和团聚。针对Al2O3SiCwSiCnp复合陶瓷刀具粉体，分别使用添加CMC为分散剂的蒸馏水介质、单纯的乙醇介质以及添加聚乙二醇为分散剂的乙醇介质对复合粉体进行了分散，通过超声振动、机械搅拌和球磨加以混合。对分散混合后的复合陶瓷粉体的微观形貌进行观察，并对烧结后的刀具材料的力学性能进行对比研究。结果表明，当采用乙醇为分散介质、聚乙二醇为分散剂时，复合陶瓷粉体的分散效果最佳，其机理在于聚乙二醇在乙醇介质中通过空间位阻稳定机制使SiC晶须吸附在其分子链的锚固基团上，防止SiC晶须发生团聚缠绕和重力沉淀。良好的粉体分散效果有助于提高刀具材料的烧结致密度，促进SiC晶须优良性能的充分发挥，提高刀具材料的综合力学性能。

关键词：复合陶瓷刀具粉体；SiC晶须；分散混合；聚乙二醇

中图分类号：TG711；TH161；TB332文献标志码：ADOI：10.3969/j.issn.1000-7008.2019.09.006

Study on Dispersing & Mixing Process of Al2O3SiCwSiCnp

Composite Ceramic Cutting Tool Material Powder

Liu Xuefei，Liu Hanlian，Huang Chuanzhen，Wang Limei，Yao Peng，Liu Lu

Abstract:SiC whiskers (SiCw)，a kind of onedimensional material，have high elasticity modulus and tensile strength and are commonly used as toughening and reinforcing phase of ceramic tool materials.However，SiC whiskers are susceptible to reunion.An Al2O3SiCwSiCnp composite ceramic cutting tool material powder is dispersed by using three different dispersion supporters：distilled water medium with CMC as dispersant，pure ethanol medium and ethanol medium with polyethylene glycol as dispersant，and then mixed by ultrasonic vibration，mechanical stirring and ball milling.The microstructures of the three kinds of dispersed composite ceramic powders are observed and the mechanical properties of sintered cutting tool materials are compared.The results show that when ethanol is used as the dispersing medium and polyethylene glycol is used as dispersant，the composite ceramic powder is dispersed best.The mechanism is that polyethylene glycol adsorbed SiC whiskers on the anchoring groups of its molecular chain through steric stabilization mechanism in ethanol medium；therefore，the agglomeration and gravity precipitation of SiC whiskers are prevented.The uniform powder dispersion promotes the sintering densification and helps SiC whiskers to full play the excellent characteristics and improve the comprehensive mechanical properties of composite ceramic cutting tool materials.

Keywords:composite ceramic cutting tool powder；SiC whiskers；dispersing and mixing；polyethylene glycol