| 摘要 |
PURPOSE:To obtain a dot printer wire improved in the toughness as well as the wear resistance by forming a coat of hard compound such as titanium carbide and titanium nitride on the surface of a tungsten wire. CONSTITUTION:A coat of hard compound such as titanium carbide, titanium nitride, alumina, silicon nitride and silicon carbide is formed on a part or whole of the surface of a tungsten wire. For example, to form a coat of titanium carbide, about 100mu of a tungsten wire 4 is introduced into a cleaning chamber 1 through a mercury seal 3 is directly energized and heated up to 1,000-1,200 deg.C in a hydrogen flow to clean the surface thereof. Then, it is introduced into a deposition chamber 2 and coated in an atmosphere of mixed gas of hydrogen, titanium tetrachloride gas and methane to form a TiC-coated tungsten wire 0.3mm. thick. It provides a tensile strength of 250-300kg/mm.<2> and a density of about 15g/cm<2>. |
