新型碳化硅基体单层CVD金刚石磨盘的制备

Preparation of New Type of SiC Matrix Monolayer CVD Diamond Grinding Wheel

金刚石磨盘被广泛应用在脆硬材料加工领域。文章将机械粉碎法加工而成的金刚石磨料混入光刻胶溶液中,通过甩胶机将光刻胶均匀地甩在碳化硅基体表面以使磨料均匀分布在基体表面。再利用热丝化学气相沉积法(Hot filament chemical vapor deposition,HFCVD)在金刚石磨粒与碳化硅磨盘基体之间沉积一层金刚石薄膜并将其连结起来,制造出碳化硅基体单层CVD金刚石磨盘。由于生长的金刚石涂层与磨粒和基体间均可形成牢固的化学键结合,因此磨粒与基体间具有较强的结合力。对磨盘进行了对磨试验以检测磨盘与磨粒的结合强度。在SEM下观察到金刚石磨料和基体通过金刚石涂层连接,磨料晶粒得到了修补和生长,粒度长大约8~9μm,针状和片状的金刚石晶粒经过CVD法生长后晶粒饱满度值提高,变得晶型完整,自形面清晰。拉曼光谱检测结果显示生长后的磨粒金刚石峰尖锐,石墨峰低,表明金刚石纯度高、缺陷少、石墨及非晶碳含量很少。在对磨试验中,CVD金刚石磨盘磨粒脱落现象远少于电镀磨盘,表明CVD金刚石磨盘对磨料有高的把持力。CVD金刚石磨盘的磨粒裸露度高,对磨后粘连的磨屑不易发生堵塞。磨粒的断裂、破碎、磨钝现象都显著少于电镀金刚石磨盘。

Diamond grinding disc is widely used for processing of hard and brittle materials.In this article,diamond abrasives processed by mechanical attrition were mixed up into the photoresist solution and then the photoresist was evenly sprayed onto the surface of SiC matrix by photoresist spinner.Then a diamond film was deposited between diamond abrasive particles and SiC grinding disc matrix through HFCVD(Hot filament chemical vapor deposition)method to bond them together to produce a SiC matrix monolayer CVD diamond grinding disc.As strong chemical bond forms between diamond coating,abrasive particles and matrix,there is a strong adhesion between abrasive particles and matrix.Adhesive strength between grinding disc and abrasive particles has been tested by grinding experiment.It is observed by SEM that the diamond abrasives and matrix were connected by diamond coating and the abrasive particles were repaired and developed,with a particle size of about 8~9μm.After CVD development,plumpness of acicular and flaky diamond particle has been improved and presents perfect crystallite shape with clear idiomorphic surface.Raman spectra shows that the developed abrasive particle has a sharp diamond peak and low graphite peak,which indicates that the diamond is of high purity and low imperfections with very few graphite and amorphous carbon.Under grinding experiment,the obscission of abrasive particle for CVD diamond grinding disc is much less than that of the electroplated grinding disc.This means the CVD diamond grinding disc has a strong bonding to the abrasives.The abrasive particles of CVD diamond grinding disc have a high degree of exposure and the abrasive dust is not prone to clogging.The fracture,breakage and blunt phenomenon of abrasive particle of CVD diamond grinding disc is significantly less than that of the electroplated grinding disc.