Co对原位合成WC-6Co复合粉末制备高性能硬质合金的影响

Research of Co in high performance cemented carbide produced from In-situ synthesis WC-6Co composite powder

将原位合成的WC-6Co复合粉末添加到300 L、转速50 Hz滚动球磨中湿磨,添加Co粉、晶粒长大抑制剂、石蜡、酒精,湿磨48 h,卸料、过孔径45μm筛,采用闭式压力喷雾干燥塔制备得到WC-7Co^WC-15Co混合料粉末,对制备混合料粉末形貌、粒度分布、物相、成分进行分析,结果表明:添加Co粉配成WC-Co混合料,当混合料的Co质量分数超过10%,团聚现象明显增强,团聚颗粒明显增大;随着添加Co粉质量分数增加,混合料中氧质量分数增高,松装密度不断减小.将制备得到的WC-7Co^WC-15Co混合料掺成型剂,挤压成型,低压烧结等工序制备超细YG7X^YG15X硬质合金.研究添加不同Co质量分数WC-6Co复合粉末制备YG7X^YG15X超细硬质合金,Co对制备硬质合金的金相组织、形貌、物理力学性能的影响,结果表明:随着添加Co质量分数增加,制备的超细硬质合金硬度、密度不断降低,抗弯强度和断裂韧性先增大、后减小;制备的超细YG7X硬质合金的硬度最高HV 30为2150,抗弯强度最低为3200 MPa;制备YG10超细硬质合金的抗弯强度最高为4950 MPa,断裂韧性最高为11.8 MPa·m 1/2.

Put the in-situ synthesis WC-6Co composite powder into 300 L rolling ball mill with the rotation speed of 50 Hz to carry out wet milling.Add Co powder,grain size growth inhibitor,paraffin,alcohol,and perform wet milling for 48 h,discharge and sieve by mesh with diameter of 45μm.After Using closed pressure type spray drying tower to produce WC-7Co to WC-15Co mixture powder and analyzing the morphology,grain size distribution,phase and constituent,it is found that when the Co in WC-Co mixture exceeds 10%,it has more powder agglomerate,and the agglomeration size is larger.With the increasing of Co powder,the oxygen also increase while the apparent density is decreasing.Then produce ultra-fine size YG7X to YG15X ultra-fine cemented carbide through adding forming agent to the prepared WC-7Co^WC-15Co mixture powder,pressing,low pressure sintering and etc.In the YG7X^YG15 Xultra-fine cemented carbide prepared by WC-6Co composite powder with different content of Co,research the influence of different Co content to the Metallographic,morphology,physic and mechanic properties.The results show that with the Co content increasing,the hardness and density of produced ultra-fine size cemented carbide are decreasing,while the bending strength and fracture toughness are increasing at first then decreasing.The ultra-fine size YG7 cemented carbide maximum HV30 hardness is 2150,the minimum bending strength is 3200 MPa.The ultra-fine size YG10 cemented carbide maximum bending strength is 4950 MPa,and the maximum fracture toughness is 11.8 MPa·m 1/2.