热丝CVD金刚石薄膜涂层工具的制备技术及应用研究

Manufacturing Technology and Application of Hot Filament CVD Diamond Film Coated Tools

本文通过电子增强热丝CVD方法在硬质合金基体上沉积金刚石薄膜 ,对硬质合金基体进行酸洗、表面研磨处理后用气相沉积方法沉积约 1μm厚的金属W膜层 ,在形核初期采用逐渐升高的偏流以去除表面形成的非晶C膜 ,并增加金刚石的形核密度和增强W的扩散作用 ,形成多种W -C化合物以增强金刚石薄膜与硬质合金基体的结合力 ,通过这种工艺制备了与基体结合力良好的金刚石薄膜。采用两种途径制备金刚石薄膜涂层工具 ,其一为在YG6硬质合金圆片上沉积约 80 μm的金刚石薄膜 ,经激光切割成 6mm× 6mm的合金片 ,用砂轮抛光 ,焊接在钢制刀柄上 ,经刃磨后制作成木工工具刀头 ;另一是直接在YG6硬质合金钻头这种复杂形状工具上沉积约 10 μm厚的金刚石薄膜制成金刚石工具。对两种工具分别进行使用性能测试 ,木工工具用于加工Al2 O3 复合木地板 ,测试结果表明金刚石薄膜涂层木工工具与硬质合金工具相比 ,使用性能有明显提高 ,寿命提高一倍以上 ,但由于刀刃后角处无金刚石层保护 ,使用中出现明显的后角磨损 ,未能达到理想效果 ;金刚石涂层钻头用于加工硬质合金时在使用初期有明显效果 ,但由于磨损很快 ,使用寿命低 ,经观察分析 ,主要是由于金刚石膜晶粒粗大造成表面光洁度不高 ,使用中刀刃处的金刚石薄膜涂层易于出现应力集中?

This paper prepared diamond films by electron enhance hot filamant CVD. WC alloy substrates are washed by acid and polished by diamond powder, then about 1 μm thick W membrane is prepared on substrates. In initial stage of nucleus forming gradually elevatory bias current is applied to wipe off C films and enhance the diffusion of W metal, and adhesion of diamond films. Diamond film tools are prepared by two ways, the first is depositing about 80μm diam ond film on 6mm×6mm C alloy wafer, the wafer is incised by laser, polished by grinding wheels, jointed on steel handles, and sharpened to make wood cutting tools heads,the other is depositing diamond films on complex shape tools such as drills. These two kinds of tools are tested for machining performance. Wood cutting tools are applied on the Al 2O 3 and wood composite, the results indicated that the machining performance and life of diamond coated tools imporved remarkably compared to WC alloy tools, but cannot achieve ideal effects because of back angle abrasion. Diamond coated drills achieved good effect in initial stages of WC alloy machining, but the diamond film is prone to be frayed because of stress centralized on too large granules. The key technique of settlement of the first problem is to grow diamond film thicker than 300μm so that the back angle abrasion present on diamond film, the property of this tool would be better than that of the composite wafer. The second is to prepare micro grain diamond films and change the form of actual drills, then the smoothness of diamond films will be improved, odd abrasion will be avoided, diamond films could be applied in super hard materials machining.