Aiming to improve the protection of human health and the environment, REACH regulation was enforced across European Union, accelerating the need to find alternative solutions to the electrodeposition processes of hexavalent chromium employed in several industrial applications. Electroplated chromium coatings are widely used due to their physical and mechanical properties that allow a longer service life of products that usually fail due to wear. Minting is one of those applications where good mechanical and tribological properties are required and where hard chromium has an important usage without being outmatched by other coatings.

This study presents the development of an alternative coating to hard chromium with outstanding mechanical properties, in particular high resistance to cyclic loads. Cr(Al,Si)N coatings have been produced by reactive DC magnetron sputtering.

Focusing on mechanical properties, an increase in the hardness was observed with the consecutive addition of elements to the base matrix (CrN), ranging from ≈10 GPa in CrN coatings up to ≈17 GPa for the CrAlSiN coatings.

In nano-impact tests, CrAlN coatings had the best performance and no crack events by fatigue were observed by SEM after 50 impacts, with load maximum 20mN, with an estimated maximum contact pressure of 1.5 GPa much higher than the one requested for coinage. The fatigue wear was governed by the H/E ratio and plasticity index showing that Cr(Al,Si)N coatings deposited by reactive magnetron sputtering can be considered excellent candidates for cyclic loading, as in minting applications.

为了改善对人类健康和环境的保护，REACH法规在整个欧盟范围内得到了执行，从而加速了寻找在几种工业应用中采用的六价铬电沉积工艺替代解决方案的需求。电镀铬涂层由于其物理和机械性能而被广泛使用，可以延长通常由于磨损而失效的产品的使用寿命。铸造是要求良好的机械和摩擦学性能且硬铬具有重要用途而又不被其他涂层超越的那些应用之一。

这项研究提出了一种替代硬质铬涂层的方法，该涂层具有出色的机械性能，尤其是对循环载荷具有很高的抵抗力。Cr（Al，Si）N涂层是通过反应性直流磁控溅射制备的。

着眼于机械性能，随着向基础基质（CrN）中连续添加元素，观察到了硬度的增加，范围从CrN涂层中的≈10GPa到CrAlSiN涂层的≈17GPa。

在纳米冲击试验中，CrAlN涂层具有最佳性能，在50次冲击后，SEM未观察到疲劳引起的裂纹事件，最大载荷为20mN，估计的最大接触压力为1.5 GPa，远高于铸币要求的压力。疲劳磨损受H / E比和可塑性指数支配，表明通过反应磁控溅射沉积的Cr（Al，Si）N涂层可被视为循环载荷的极佳候选材料，如在铸币应用中。