Zhang Xinyu, Qin Jiaqian, Das Malay Kumar, Hao Ruru, Zhong Hua, Thueploy Adisak, Limpanart Sarintorn, Boonyongmaneerat Yuttanant, Ma Mingzhen, Liu Riping
State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, P.R. China.
Metallurgy and Materials Science Research Institute, Chulalongkorn University, Bangkok 10330, Thailand.
Sci Rep. 2016 Feb 29;6:22285. doi: 10.1038/srep22285.
Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.
电镀硬铬涂层作为一种耐磨涂层被广泛应用于延长机械部件的使用寿命。然而，电镀过程会产生六价铬离子，这是一种已知的致癌物。因此，整个电镀行业都在大力努力替换硬铬涂层。复合涂层已被确定为替代硬铬涂层的合适材料，而使用传统共沉积技术制备的沉积涂层颗粒含量相对较低，但掺入涂层中的颗粒含量可能会从根本上影响其性能。在本研究中，通过在含有悬浮金刚石颗粒的镍 - 钨镀液中进行沉淀共电沉积制备了镍 - 钨/金刚石复合涂层。本研究表明，较高含量的金刚石能够成功地共沉积并均匀分布在镍 - 钨合金基体中。由于金刚石含量最高可达64 wt.%，镍 - 钨/金刚石复合涂层的最大硬度达到2249 ± 23 Hv。在氩气中于873 K热处理1 h后，硬度可进一步提高至2647 ± 25 Hv，这与硬铬涂层相当。此外，添加金刚石颗粒可显著提高涂层的耐磨性。
