摘要
Cr/CrN multilayer coatings with bilayer periods in the range from 1351 to 260 nm were prepared on 304 stainless steel substrates by arc ion plating to study the microstructure and properties of multilayer coatings and stimulate their application.SEM results confirm the clear periodicity of the Cr/CrN multilayer coatings and the clear interface between individual layers.XRD patterns reveal that these multilayer coatings contain Cr,CrN and Cr_2N phases.Because Cr layer is softer than its nitride layer,the hardness decreases with the shortening of the bilayer period(or increasing volume fraction of Cr layer).The Cr/CrN multilayer coating with 862 nm period possesses the highest indentation toughness due to a proper individual Cr and nitride layer thickness.However,for the Cr/CrN multilayer with the bilayer period of 1351 nm,it possesses the lowest toughness due to more nitride phase.The indentation toughness of Cr/CrN multilayer coatings is related with their bilayer period.A coating with a proper individual Cr and nitride layer thickness possesses the highest indentation toughness.
采用电弧离子镀在304不锈钢衬底上制备双层周期为1351260 nm的Cr/CrN多层膜。扫描电镜清晰地显示Cr/CrN沉积膜的多层结构和层界。X射线衍射谱显示沉积的多层膜含有Cr、CrN和Cr2N相。随着沉积膜双层周期的增加,制备的多层膜的硬度和弹性模量略有增加,但是所有多层膜的硬度和弹性模量都低于单层CrN膜的硬度和弹性模量。因为Cr层比其氮化物层软,所以多层膜的硬度随双层周期的缩短或Cr层体积分数的增加而减小。由于具有适当厚度的Cr层和氮化物层,双层周期为862 nm的Cr/CrN多层膜的压痕韧性最高。然而,由于拥有更多的氮化物相,双层周期为1351 nm的Cr/CrN多层膜的压痕韧性最低。Cr/CrN多层膜的压痕韧性与双层周期有关,具有适当厚度Cr层和氮化物层的Cr/CrN多层膜具有最高的压痕韧性。
基金
Project(51171118)supported by the National Natural Science Foundation of China
Project(2012-4)supported by the Liaoning Provincial Key Laboratory of Advanced Materials,Shenyang University,China
