摘要
在加热温度920℃和保温时间30 min工艺下,进行铜锡钛(Cu-Sn-Ti)合金与石墨颗粒、聚晶立方氮化硼(PCBN)磨粒的烧结试验.通过三点抗弯试验测试了烧结试样的强度,并使用扫描电镜、能谱仪、X射线衍射仪检测了复合块的断口形貌与物相组成.结果表明,石墨质量分数为5%～15%时烧结试样的抗弯强度达91 MPa以上,高于陶瓷砂轮工作层强度;试样烧结过程中发生了元素扩散,在结合界面处形成了化合物,实现了PCBN磨粒与Cu-Sn-Ti合金之间的化学结合;由于复合块对PCBN磨粒的牢固把持作用,抗弯试验过程中复合块内部的PCBN磨粒发生沿晶断裂.
Sintering experiments of Cu-Sn-Ti alloy,polycrystalline cubic boron nitride(PCBN)abrasive grains and graphite particles were carried out at the heating temperature of 920℃with the dwell time of 30 min.The strength of sintering bulks was measured by means of the three-point bending experiments.The interfacial microstructure and the phases of the sintering bulks were characterized using scanning electron microscope (SEM),energy dispersion spectrometer(EDS)and X-ray diffraction(XRD).The results reveal that in the case of the graphite content of 5～15 wt%,the bending strength of the composite bulks is above 91 MPa,which is much higher than that of the bulk strength of the vitrified grinding wheels.The elemental diffusion behavior has taken place across the joining interface between PCBN grains and Cu-Sn-Ti alloy in the sintering process.The compounds were formed,therefore,the PCBN grains were bonded firmly.Under such condition,the breakage of the PCBN grains has played the most important role in the fracture of the composite bulks.In particular,the breakage mode of the PCBN grains is the intergranular fracture.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2011年第12期63-65,69,共4页
Transactions of The China Welding Institution
基金
国家重点基础研究发展计划资助项目(2009CB724403)
国家自然科学基金资助项目(51005116)
江苏省自然科学基金资助项目(BK2010496)
中国博士后科学基金资助项目(20110490167)
