钛合金表面粗化对WC-17Co涂层结合性能的影响

研究Ti-6Al-4V合金表面不同粗糙度对超音速火焰喷涂(HVOF)碳化钨(WC-17Co)涂层结合性能的影响. 采用不同喷砂工艺对钛合金表面进行粗化预处理，得到1,2和3号试样的表面粗糙度分别为22.003,20.845和14.765 μm. 利用超音速火焰喷涂技术在粗化后的钛合金表面制备WC-17Co涂层，厚度为0.3 mm. 对WC-17Co/Ti-6Al-4V试样进行三点弯曲试验，利用扫描电镜观察界面形貌. 结果表明，3号试样的界面裂纹扩展最严重并引起了部分涂层脱落，2号试样结合最好；采用四点弯曲法测试涂层与基体的结合界面的断裂能量释放率分别为239.7,259.0和200.1 J/m2.

Effect of interfacial bonding properties of WC-17Co/Ti-6Al-4V after roughening on the face of substrate

The effect of surface roughness of Ti-6Al-4V alloy on the bonding strength of tungsten carbide (WC-17Co) coatings sprayed by high velocity oxygen fuel (HVOF) was studied. Different sand blasting processes were used to generate different surface roughness with 22.003, 20.845 and 14.765 μm for No.1, No.2 and No.3 specimens, respectively. The WC-17Co coating with a thickness of 0.3 mm was deposited on the surface of titanium alloy by HVOF technology. The three-point bending test was performed on the WC-17Co/Ti-6Al-4V sample, and the interface morphology was observed by a scanning electron microscope. It was found that cracks propagated seriously at the interface of No. 3 specimen, resulting in the coating peeling off. No. 2 sample showed the best bonding properties. The four-point bending method was used to test the fracture energy release rates between the coating and the substrate, and the values of release rate were 239.7, 259.0 and 200.1 J/m2for three specimens, respectively.