热处理对Fe基非晶合金涂层的相组成及摩擦磨损行为的影响

Effect of heat treatment on micro-structure and wear behaviors of iron-base amorphous alloy coatings

采用爆炸喷涂技术在Q235不锈钢基体上制备Fe基非晶合金涂层,在500~700℃下对涂层进行热处理,研究热处理温度对涂层的相组成和摩擦磨损性能的影响。结果表明：随热处理温度升高,涂层中非晶相含量明显减少,700℃热处理后,非晶相含量（体积分数）由热处理前的85.54%降至38.94%;热处理后涂层结构变得更致密;喷涂态涂层的平均显微硬度为1 095.6 HV0.05,500℃热处理后硬度变化不大,随热处理温度升高呈缓慢上升的趋势;与喷涂态涂层相比,500和600℃热处理后涂层的平均摩擦因数稍有增加,而700℃热处理后平均摩擦因数减小15%;热处理温度为600℃时涂层的磨损量较热处理前降低20%,耐磨性能最好,而热处理温度为700℃时涂层的质量磨损增大到热处理前的3倍以上,主要是涂层晶化相明显增加,氧化物含量增多,涂层变脆所致;磨损机制为则由喷漆态的粘着磨损向磨粒磨损,再到二者混合机制磨损转变。

Iron-based amorphous alloy coatings were synthesized on Q235 stainless steel surface by detonation gun thermal spraying.Post heat treatment was conducted in the atmospheric environment within the temperature ranged from 500 ℃ to 700 ℃.The effect of heat treatment on phase structure and wear characteristics of the coating was investigated.The results show that,with increasing heat treatment temperature,the content of amorphous phase has a obvious decrease,changing from 85.2% to 38.94% after 700 ℃ heat treatment;Iron-based amorphous alloy coatings show more dense structure after heat treatment.The average microhardness of sprayed coating before heat treatment is 1 095.6 HV0.05,and it has little change after 500 ℃ heat treatment,the microhardness increases slowly with increasing heat treatment temperature;compared with sprayed coating condition,the friction coefficients of coating increase slightly after heat treatment at 500 ℃ and 600 ℃;the friction coefficient decreases by 15% after heat treatment at 700 ℃;the wear resistance decreases by 20% after heat treatment at 600 ℃,and the best wear resistance property is obtained at this time;while the mass wear loss is 3 times of that of the sprayed coating after heat treatment at 700 ℃,which is because of the decreasing of amorphous phase and oxide in the coating resulting in coating embrittlement.The wear behaviour is changing from adhesive wear to abrasive wear,then to the mixture of the two wear mechanisms.