超声冲击对Q235钢表面等离子喷涂涂层组织及抗热震性能的影响

Structure and heat shock resistance of coating prepared by plasma spraying on the Q235 steel after ultrasonic impact treatment

利用等离子喷涂技术在Q235钢表面喷涂Mo涂层及Mo/A12O3-TiO2复合涂层,对所制备的涂层进行超声冲击处理.利用SEM等分析测试手段,研究了超声冲击前后涂层表面的宏观及微观组织形貌;通过热震试验,研究了超声冲击对涂层热震性能的影响.结果表明:超声冲击处理对复合涂层的抗热震性能影响不大,且均优于Mo涂层.但超声冲击处理对Mo涂层的抗热震性能影响较大,热震失效次数由超声冲击处理前的87次提高至超声冲击处理后的96次.Mo涂层的失效形式则主要表现为小块剥落直至最终剥落面积超过总面积的1/3而失效,复合涂层的失效形式主要表现为整体剥落.

The Mo coating and Mo/A12 O3 -TiO2 composite coating were prepared by plasma spraying on the Q235 steel;the ultrasonic impact treatment of the prepared coatings was received .Macro and micro structure of these coatings before and after the ultrasonic impact treatment were investigated by means of SEM and others . The thermal shock property of the coating by the ultrasonic impact treatment was studied .The results show that：ultrasonic impact treatment has little effect on the thermal shock resistance of the composite coating and is better than the Mo coating .But there is bigger impact on the thermal shock resistance of the Mo coating by the ultrason -ic impact treatment .The number of times for thermal shock failure of Mo coating after the ultrasonic impact treat-ment increased to 96 from 87 before the Ultrasonic impact treatment .The main thermal shock failure performance of the Mo coating is that the coating surface was flaked by small pieces till 1/3 proportion of the all coating flaked then the coating completely failed , and the main thermal shock failure performance of the composite coating is flaked by a whole piece .