ZnO/Na_2O(mol)对cBN陶瓷砂轮性能的影响  

Effect of ZnO/Na_2O(mol) on the Properties of cBN Vitrified Bond Grinding Wheel

作　　者：万隆[1] 翟浩冲[1] 胡伟达[1] 刘小磐[1] 张国威[1] 王志起[1] 

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2011年第9期64-69,共6页Journal of Hunan University:Natural Sciences

基　　金：湖南省科技厅资助项目(2009GK3140);长沙市科技计划项目(K09050121-11)

摘　　要：通过DSC-TG综合热分析、X衍射分析、线膨胀测试仪、扫描电镜等测试方法研究了ZnO/Na2O(mol)(Z值)对Li2O-K2O-SiO2-Al2O3-B2O3系陶瓷结合剂及立方氮化硼砂轮性能的影响,结果发现:ZnO能够抑制α-石英晶相析出,诱导析出低膨胀晶体Li2OAl2O37.5SiO2,并随着Z值的增加,α-石英减少,Li2OAl2O37.5SiO2晶体逐渐增多,Li2OAl2O37.5SiO2晶型结构趋于完整,晶粒尺寸减小,结构更加致密;当砂轮配方一定时,砂轮的体积密度、抗弯曲强度、洛氏硬度均随着Z值的增加而增大,气孔率减小,磨削(干磨)铸铁(QT400)时磨耗比先增加后减小;当Z=0.75时,结合剂的膨胀系数为6.902 9×10-6 K-1,耐火度为805℃,砂轮的烧结温度为845℃,抗弯曲强度为73.97MPa,气孔率为15.65%,磨耗比最大为156.42%.The effect of ZnO/Na2O molar ratio（Z）on the properties of Li2O-K2O-SiO2-Al2O3-B2O3 system vitrified bonds and cBN grinding wheels were studied with TG-DSC,X-ray diffraction analysis,scanning electron microscopy and thermal expansion coefficient tests.The results showed that the lower inflation crystalline phase（Li2OAl2O37.5SiO2）appeared in the vitrified bond.And by increasing the ratio of Z,all the vitrified bonds＇ topographic crystal temperature,softening temperature,crystal quantity and density increased while the crystal size was reduced.When the wheel formula was fixed,the porosity of wheel decreased by increasing the ratio of Z while the bulk density,hardness and bending strength all increased.But G-ratio（dry-rubbing QT400）increased at the beginning,and then became lower.When the ratio of Z was 0.75,the values of vitrified bonds＇ expansion coefficient and softening temperature were 6.902 9×10-6K-1 and 805 ℃,respectively.Meanwhile,the bending strength,the porosity and G-ratio of cBN grinding wheel were 73.97 MPa,15.65% and 156.42%,respectively.

关 键 词：砂轮 陶瓷结合剂 立方氮化硼 抗折强度 磨耗比 

分 类 号：TG74[金属学及工艺—刀具与模具]