Cu含量对铁基中熵合金涂层组织与性能影响

Effect of Cu Content on Microstructure and Properties of Iron-based Medium Entropy Alloy Coating

采用激光熔覆方法制备了(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(100-x)Cu_(x)(x=0,1%,3%,5%,7%,原子百分数,下同)中熵合金涂层。研究了Cu元素含量对涂层物相结构、微观组织、显微硬度和耐蚀性能的影响。结果表明,随着Cu元素含量增加,合金涂层均为单一的FCC结构,呈典型树枝晶结构。显微硬度均高于基材304不锈钢,且随着Cu元素含量增加呈递减趋势。在3.5%NaCl溶液中,(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99)Cu_(1)中熵合金涂层的腐蚀电位最高,相比基材304不锈钢向正方向移动了29 mV,且具有最低的腐蚀电流密度为4.977×10^(-6)A/cm^(2),涂层表面腐蚀主要发生轻微的晶界腐蚀。(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(100-x)Cu_(x)合金涂层中Cu元素含量较低时,涂层具有较高的硬度和耐蚀性能,具有良好潜在的价值。

The medium entropy alloy coatings(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(100-x)Cu_(x)(x=0,1 at.%,3 at.%,5 at.%,7at.%)were prepared by laser cladding method.The effects of Cu content on phase,microstructure,microhardness and corrosion resistance of the coatings were investigated.The results show that with the increase of Cu element content,the coatings all possess a single FCC phase with a typical dendritic structure.The microhardness decreases with the increase of Cu content,but it is higher than that of 304 stainless steel.In 3.5%NaCl solution,(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(99)Cu_(1)medium entropy alloy coating exhibits the highest corrosion potential,which moves 29 mV in the positive direction compared with 304 substrate,and the lowest corrosion current density of 4.977×10^(-6)A/cm^(2),the coating surface corrosion mainly occurs slight grain boundary corrosion.(Fe_(63.3)Mn_(14)Si_(9.1)Cr_(9.8)C_(3.8))_(100-x)Cu_(x)alloy coating with low Cu content has high hardness and corrosion resistance,and optimal potential value.