CVD金刚石薄膜在钨丝和碳纤维上的制备

用CVD方法在钨丝和碳纤维上沉积金刚石薄膜，约含有10000根纤维的纤维束经特殊处理后分离为单根，生长条件使碳纤维中心在CVD生长结束后仍保持固态，CVD金刚石在纤维上生长的平均激活能为93.15KJ/mol。SEM照片给出了纤维涂层在不同生长条件下的表面和中心的形貌。纤维内部的石墨碳和外部的金刚石层有很大的不同。钨丝的断裂强度和杨氏模量的测量表明，具有金刚石涂层的钨丝的断裂强度为0.567GPa，非常接近不具有金刚石涂层的钨丝的断裂强度，但具有金刚石涂层的钨丝的断裂应变为4.8%，比没有金刚石涂层的钨丝的新裂应变7%要小得多，这表明了金刚石涂层可以减少钨丝的断裂应力，提高其机械性能。

Preparation of CVD diamond coatings on W wire and C fiber

Diamond growth on W－wire and C－fiber substrates was studied. A treatment was used to separate fibers one by one from a bunch of more than 10000 fibers. The selected growth condition was to keep the carbon fiber core solid after CVD growth. Activation energy of CVD coated fibers is 93.15 kJ/mol in average. SEM pictures show surface and core morphology of the coatings under different treatment conditions. There are two different contrasts related to interior graphite carbon and exterior diamond layer. Wire fracture strength and Young's modulus measurement indicates that the fracture strength of W wire with diamond coating is 0.567 GPa, very close to its value without coating. However, the fracture strain of the wire with diamond coating is 4.8％ , which is much less than that of W wire fracture strain of 7％ . It means that diamond coated wire may reduce wire fracture strain and improve its mechanical property.