超音速火焰喷涂制备WC-12Co薄涂层的进展

Development of Thin WC-12Co Coatings Manufactured by HVOF-Spraying

HVOF 喷涂制备WC-12Co 耐磨涂层的厚度通常在50 至500μm 之间,这个厚度既可以确保涂层结构均匀,同时也保证了足够的材料储备用来进行有效的磨损保护.对于表面需要高精度的零部件,厚涂层必须采用成本高昂的精准加工、磨削和抛光工艺.因此,制备光滑的薄涂层是非常有必要的.在本研究中,HVOF 工艺以细的团聚烧结型WC-12Co 粉末（2 ～ 10μm）为原料制备薄碳化物涂层,涂层厚度可降至50μm 以下.本论文系统研究了送粉速度、喷枪速度和轨道间距的变化对涂层厚度的影响,并重点研究了涂层的硬度和表面粗糙度的变化.

The thicknesses of HVOF-sprayed WC-12Co wear protective coatings usually range between50 ～ 500μm. These thicknesses ensure a homogeneous coating structure as well as sufficient material reservesfor an efficient wear protection. For applications which require high shape accuracies, a cost intensive finishing ofthe thick coatings, in terms of grinding and polishing, is necessary. Thus, smooth and thin coatings are favored. Inthis study, thin HVOF-sprayed carbide coatings are developed by means of fine sintered and agglomerated WC-12Co powders （2 ～ 10μm）. The use of fine powders enables the reduction of the coating thickness down tovalues below 50μm. To influence and adjust the thickness of the coatings the powder flow, the gun velocity andthe track pitch were systematically varied. During these tests the hardness and the roughness of the coatings werescrutinized.