工艺参数对超音速火焰喷涂Fe基非晶涂层性能的影响

Fe基非晶涂层具有优异的耐磨、耐蚀性能,以及较高的性价比,适合在表面防护涂层领域广泛应用。本文通过正交试验研究了煤油流量、氧气流量、送粉速率、喷涂距离对超音速火焰喷涂制备的Fe基非晶涂层的孔隙率、硬度、耐磨性能的影响。采用图像法、显微硬度计和摩擦磨损试验机分别对Fe基非晶涂层的孔隙率、硬度、耐磨性能进行了表征。采用X射线衍射仪和扫描电镜分别对涂层的相组成和显微结构进行了表征。通过极差分析法分析得出以涂层孔隙率最低为目标的优化制备工艺,最佳喷涂工艺参数为:煤油流量0.41 L/min,氧气流量830 L/min,喷涂距离430 mm,送粉速率40 g/min。结果表明:送粉速率和氧气流量对涂层孔隙率影响较大,进而影响涂层的硬度及耐磨性能。孔隙率随着氧气流量和送粉速率的增加而增加,随着煤油流量和喷涂距离的增加而降低。制备的Fe基非晶涂层硬度达到1158.9HV0.2,孔隙率为1.22%,磨损实验的质量损失量只有316L不锈钢的一半。

Influence of Spray Parameters on the Properties of HVOF Sprayed Fe-based Amorphous Coating

Fe-based amorphous coatings can be applied intensively in many industries to protect metal parts surface, due to their excellent wear resistance, as well as high cost performance. In this work, the influences of the kerosene flow rate, oxygen flow rate, powder feeding rate and spray distance on the porosity, microhardness and wear resistance of the HVOF sprayed Fe-based amorphous coatings were investigated, through designing orthogonal experiment. The porosity, microhardness and wear resistance of the Fe-based amorphous coatings were characterized by image method using Image-J software, microhardness tester, as well as abrasive wear tester, respectively. The phase compositions of the Fe-based feedstock and the as-sprayed correspongding coatings were analyzed by X-ray diffraction method. The microstructures of the Fe-based coatings were characterized by scanning electron microscopy.The spray parameters were optimzed in order to obtain the coating with minimum porosity by the range analysis. The optimized spray parameters were kerosene flow rate of 0.41L/min, oxygen flow rate of 830L/min, spray distance of 430mm and powder feeding rate of 40g/min. The experimental results showed that, the powder feeding rate and oxygen flow rate have a great influence on the porosity of the coating, which in turn affect the coating microhardness and wear resistance. The porosity of the coaitng increases with an increase of oxygen flow rate and powder feeding rate, and decreases with increasing kerosene flow rate and spray distance. The microhardness of the as-sprayed Fe-based amorphous coatings can reach 1158.9HV_0.2, and the mass loss of the coatings after wear testing can be as low as half that of 316L stainless steel.