摘要
采用热浸镀法在45钢表面制备出了Fe-Al金属间化合物涂层,并在不同温度下对热浸镀后的试样进行扩散退火处理。通过XRD、SEM等分析手段对扩散退火后的涂层结构和成分进行测试分析,探讨扩散退火温度对涂层的影响及合金层的转变机理。结果表明:扩散温度为700~800℃,合金层主要物相为Fe2Al5和Al2O3;800℃以上时,随着温度的升高,合金层的物相由脆性相(Fe2Al5)向韧性相(FeAl和Fe3Al)转变;1 000℃时合金层完全转变为FeAl和Fe3Al。Fe2A5硬度高但脆性大,易产生裂纹,虽然FeAl和Fe3Al的硬度与Fe2A5的硬度相比有所降低,但其韧性好能有效阻碍裂纹产生及扩展,并与基体结合更加致密。
Fe-Al intermetallic matrix composite coating was prepared on the surface of steel C45 by hotdip aluminizing,then the sample was processed at different diffusion annealing temperature. The structures and chemical compositions of the coating were analyzed by XRD and SEM etc. The effect of diffusion annealing temperature on alloy layer and the conversion mechanism of the layer was discussed. The results show that the main phases of the coating are Fe2Al and Al2O3 when the temperature is at 700~800 ℃; as the temperature exceeds 800 ℃,the phase of the alloy layer varies from brittle phase( Fe2Al5) to tough phases(FeAl and Fe3Al); the alloy layer is completely converted to FeAl and Fe3Al when the diffusion temperature is at 1 000 ℃. Fe2Al5 is featured by great hardness but it tends to crack due to its brittleness. Although the hardness of FeAl and Fe3Al is lower than that of Fe2A5,their toughness is so excellent that they can effectively hinder the formation and expansion of cracks in the coating,and they can integrate closer with the matrix.
出处
《钢铁钒钛》
CAS
北大核心
2013年第5期95-98,104,共5页
Iron Steel Vanadium Titanium
基金
国家自然科学基金项目(51071078)
江苏省高校摩擦学重点实验室开放项目(kjsmcx1004)
关键词
热浸镀铝碳钢
热扩散温度
FE3AL
FEAL
涂层的物相
hot-dip aluminized carbon steel
diffusion annealing temperature
Fe3Al
FeAl
phase of coating
