偏压对CrN涂层结构与海水环境摩擦学行为的影响

Effect of Bias on Microstructure and Tribological Behavior in Artificial Seawater of Cr N Coatings

利用多弧离子镀技术在M2高速钢和p(100)单晶硅片上用不同偏压条件分别制备了4种CrN涂层,考察了涂层的显微结构、力学性能、海水环境中的电化学特性与摩擦学行为,分析了涂层的裂纹形貌与断裂机制.结果显示:交替偏压下制备的多层CrN涂层内部结构致密且硬度与择优取向梯度变化,具有高的膜基结合力(Lc大于150 N),较小的平均晶粒尺寸(70 nm),较高的自腐蚀电位(-0.234 V)和较低的自腐蚀电流(3.052×10-8A).在海水环境中与直径为3 mm的YG-6(94%WC+6%Co)硬质合金球配副,Hertzian接触应力达到3.47 GPa时,平均摩擦系数低于0.15,磨损率低于1.26×10-15m3/(Nm),磨痕内没有明显的涂层崩裂失效,耐磨损性能明显优于其余3种CrN涂层.

Mono-layer and multi-layer chromium nitride coatings were deposited on M2 high speed steel substrates and silicon wafers by multi-arc ions plating technique. Microstructure,mechanical properties including hardness,modulus and critical load,polarization curves and tribological properties in artificial seawater were investigated. Results show that multi-layer CrN performed optimally both in mechanical and friction performance. Dense structure and sophisticated intergranular boundaries induced by laddered changing bias during coating process enhanced the wear and corrosion resistance(Ecorr=-0. 234 V,Icorr= 3. 052 × 10-8A) of this multi-layer CrN obviously compared to other mono-layer ones. The average fricition coefficient less than 0. 15 when Hertzian contact stress was attained 3. 47 GPa,correspondedto relatively low specific wear rate,1. 26 × 10-15m3/(Nm) in sliding process.