摘要
超粗晶结构硬质合金拥有良好的耐磨性、韧性和抗热冲击、抗热疲劳性能,广泛应用于石油钻齿、凿岩钎具、截煤机齿、路面冷铣刨机齿、盾构刀具等地矿工具。文章对比研究了预磨细颗粒WC活化粉和纳米WC活化粉的添加对低压烧结制备的超粗晶硬质合金结构与性能的影响,采用金相显微镜和电子万能试验机等检测方法对其进行组织结构及力学性能的表征,使用扫描电镜对试样条断口进行形貌分析。研究了球磨时间、预磨粉末粒度对超粗晶硬质合金晶粒度、抗弯强度等性能的影响。试验结果表明,相比添加细颗粒WC粉,添加纳米WC粉制备的超粗晶硬质合金的平均晶粒度增加更为明显。随球磨时间增加,合金组织均匀性提高,抗弯强度升高。添加5%(质量分数,下同)预磨纳米WC,球磨18 h制备的超粗晶硬质合金晶粒度达6.8μm,抗弯强度2640 MPa,具有最佳综合力学性能。
Featuring good wear resistance,toughness,thermal shock resistance and thermal fatigue resistance,and Ultra-coarse grained hard alloy is widely used in geological and mining tools such as oil drilling teeth,rock drilling tools,coal cutter teeth,cold milling machine teeth for road surface,shield cutters,etc.In this paper,the effects of the addition of pre-milled WC activated powder and nano-WC activated powder on the structure and properties of ultra-coarse grained cemented carbide prepared by low pressure sintering were studied comparatively.The microstructure and mechanical properties were characterized by metallographic microscope and electronic universal testing machine,and the fracture surface of the sample strip was analyzed by scanning electron microscope.The effects of ball milling time and particle size of pre-milled powder on the grain size and bending strength of ultra-coarse grained hard alloy were studied.The experimental results show that the average grain size of ultra-coarse grained cemented carbide prepared by adding nano-WC powder increases more obviously than that by adding finegrained WC powder.With the increase of ball milling time,the microstructure uniformity and bending strength of the alloy increase.The ultra-coarse cemented carbide prepared by adding 5%(mass fraction)of pre-milled nano WC and ball milling for 18 h has a grain size of 6.8μm and a bending strength of 2640 MPa,and has the best comprehensive mechanical properties.
作者
汤昌仁
梁瑜
郭永忠
陈玉柏
杨树忠
TANG Changren;LIANG Yu;GUO Yongzhong;CHEN Yubo;YANG Shuzhong(Jiangxi Tungsten Holding Group Co.,Ltd.,Nanchang 330096,Jiangxi,China;Jiangxi Jiangwu Cemented Carbide Co.,Ltd.,Jingan 330699,Jiangxi,China;Ganzhou Nonferrous Metallurg Research Institute,Ganzhou 341000,Jiangxi,China)
出处
《中国钨业》
CAS
2019年第4期41-46,共6页
China Tungsten Industry
基金
国家重点研发计划项目(2017YFB0305900)
关键词
超粗晶硬质合金
纳米WC
球磨时间
粉末粒度
抗弯强度
ultra-coarse crystal hard alloy
nano WC powders
ball milling time
powder size
bending strength
