富铈合金改性镍基钎料钎焊金刚石钻头的性能研究

Study on Performance of Brazed Diamond Drill Bits with Ce-rich Modified Ni-Cr Brazing Alloy

Ni-Cr合金钎料对金刚石磨料会造成热损伤,影响了钎焊金刚石钻头加工性能的进一步提高。提出了Ni-Cr合金和富Ce合金复合钎料制备新型钎焊金刚石钻头和试样,开展了3种钎焊钻头钻削玻化砖的加工性能实验研究,利用扫描电镜分析了3种钎焊金刚石试样表面微观形貌和钎焊钻头的磨损形貌。结果表明:采用复合钎料制备的钎焊金刚石试样,金刚石磨料表面蚀坑较少,金刚石磨料表面或附近微裂纹较少,表面形貌优于Ni-Cr合金钎料钎焊金刚石试样;与Ni-Cr合金钎焊金刚石相比,富Ce合金添加量为5%和10%的复合钎料钎焊金刚石残余应力分别减少9.7%和16.1%;与Ni-Cr合金钎料钎焊金刚石钻头相比,采用富Ce合金添加量为5%的复合钎料制备的钎焊金刚石钻头其使用寿命增加60%,加工效率提高30.7%,磨损形式主要为微观破碎和宏观破碎,具有最优的加工性能和磨损形貌;富Ce合金能降低Ni-Cr合金对金刚石造成的热损伤。

Ni-Cr alloy can cause thermal damage to diamond thereby limit the further improvement of the machining performance of brazed diamond drills. A composite consisting of Ni-Cr alloy and Ce-rich alloy was proposed to prepare new brazed drill bits and samples. Drilling tests on vitrified titles were carried out. The morphology of brazed samples and drill bits after drilling were studied. Results show the surface morphology of brazed samples with the composite was better than that of counterparts with Ni-Cr alloy. The thermal residual stresses values of brazed diamonds with the composite containing 5% or 10% Ce-rich alloy were decreased by 9.7% or 16.1%, comparing with that of counterparts with Ni-Cr alloy. The tool life and the machining efficiency of brazed drill bit with the composite containing 5% Ce-rich alloy were increased 60% and 30.7%, respectively, comparing with that of counterparts with Ni-Cr alloy. The main wear forms were micro-and macro-fracture. Ce-rich alloy can reduce the thermal damage to diamonds caused by Ni-Cr alloy.