摘要
采用石蜡基多聚合物粘结剂体系，通过注射成型制备了WC-10％Co硬质合金的ZTKD型号切断切槽刀片试样。通过脱察该月片注射坯及断口形貌，分析注射坯的缺陷情况和质量变化等，研究了温度、压力、保雎时间等参数对WC-10％Co硬质合金注射成型性能的影响，确定了优化值，该注射成型刀片最佳参数为注射温度110℃、注射压力150MPa，保压压力为120MPa，保压时间为2．5-3．08。结果发现，注射温度、注射压力对注射结果影响最大；注射温度太低，喂料流动性不足，温度太高，将容易产生粉末与粘结剂两相分离；随着注射压力加大，注射坯密度也增大，并趋向一最大值，但压力过大，残余应力也大，产品容易变形、裂纹等，脱模也困难；为有效释放注射坯内应力，保压压力应低于注射压力，保压开始阶段，注射坯密度增加明显，随着保压时间的延长，保压压力与注射坯浇口处反作用力达到平衡，密度不再增加。
A type of ZTKD WC-10%Co cemented carbide insert for cutting tool was fabricated by powder injection moulding with wax-based multi-polymer as binder. The effects of the temperature, pressure and holding time in the injection moulding on the properties of the WC-10%Co cemented carbide were researched by observing the appearance surface and the fracture surface as well as analyzing the defects and weight changes of the injected green parts. The experiments show that 110 ~C, 150 MPa and holding at 120 MPa for 2.5-3 s are the optimum injection moulding parameters of the insert. It is even showes that the temperature and pressure primarily affect the quality of the injection part. If the injection temperature is too low, the flowability of the feedstock is not enough, which results in the separation of the powder from the binder. The density of the injected green part increases with the increase of the injection pressure and then reaches the highest value. Reversely, if the injection pressure is too high, the residul stress inside the injectet green part is high, which results in the distortion and cracks of the part, and the demoulding of the injection part is not so easy. For effectively reducing the residul stress, the holding pressure should be lower than the injection pressure. At the start of holding the pressure, the desity of the green part distinctly inreases, then the holding pressure and the counterforee at the injecting gate are equilibrium with the prolonging of the holding time, and the density of the injected green part keeps a constant value.
出处
《硬质合金》
CAS
2013年第4期210-216,共7页
Cemented Carbides
关键词
硬质合金刀片
注射成型
注射压力
保压时间
参数优化
cemented carbide
insert
injection moulding
injection moulding pressure
pressure-holding
parameteroptimization
