| 摘要 |
PURPOSE:To improve Vickers hardness, break resistant strength, heat shock resistance, etc., of a nozzle and to extend the service life thereof by forming at least contacting part with low m.p. molten metal with boronizing titanium ceramic sintered body. CONSTITUTION:A low m.p. metal treating instrument 10 is composed of part, which is not brought into contact with the low m.p. molten metal, that is, a nozzle body 11 and a protecting layer 12. The protecting layer 12 is formed with the boronizing titanium ceramic sintered body arranging matrix layer, in which the boronizing material of at least one kind of metal selected from transition metals and titanium carbide are mixed and made to solid solution, between the boronizing titanium grains and having 5% porocity ratio. By this method, erosion of the nozzle body 11 caused by low m.p. metal is prevented and mixture of the raw material of the nozzle body 11 into the low m.p. metal is prevented. |
