Ul-Hamid Anwar
Center for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
J Adv Res. 2020 Nov 25;29:107-119. doi: 10.1016/j.jare.2020.11.010. eCollection 2021 Mar.
Hard coatings are primarily based on carbides, nitrides and carbonitrides of transition metal elements such as W, Ti, Zr, etc. Zr-based hard coatings show good resistance to wear, erosion, and corrosion as well as exhibit high hardness, high temperature stability, and biocompatibility, making them suitable candidates for tribological, biomedical, and electrical applications.
The present study aims to synthesize uniform and adherent hard Zr-based coatings that demonstrate sound mechanical integrity.
Stainless steel (SS316) samples were coated with single layers of Zr, Zr-nitride, and Zr-carbonitride using magnetron sputter deposition technique. Deposition conditions were controlled to produce each coating with two different thickness i.e., 2 and 3 μm. Calotest was employed to confirm coatings thickness. Scanning electron microscope fitted with energy dispersive x-ray spectrometer was used to ascertain the morphology and elemental constitution of coatings. Cross-sectional samples were examined to ascertain coatings thickness and adhesion. X-ray diffractometer was employed for structural analysis. Instrumented nanoindentation hardness and elastic modulus were determined with nanoindenter. Ratio of nanohardness to elastic modulus was evaluated to observe the effect of coatings thickness on tribological behavior.
Three coating compositions were produced namely hcp-Zr, fcc-ZrN and fcc-ZrCN. The highest hardness and elastic modulus were shown by ZrN coatings while pure Zr coatings showed the lowest values.
All coating compositions were found to be relatively uniform, continuous and adherent with no evidence of decohesion at the coating-substrate interface. Coatings produced in this study are thought to be suitable for tribological applications.
硬质涂层主要基于过渡金属元素（如钨、钛、锆等）的碳化物、氮化物和碳氮化物。锆基硬质涂层具有良好的耐磨性、耐侵蚀性和耐腐蚀性，同时还具有高硬度、高温稳定性和生物相容性，使其成为摩擦学、生物医学和电气应用的合适候选材料。
本研究旨在合成具有良好机械完整性的均匀且附着性好的锆基硬质涂层。
采用磁控溅射沉积技术在不锈钢（SS316）样品上涂覆单层锆、氮化锆和碳氮化锆。控制沉积条件以制备两种不同厚度（即2μm和3μm）的每种涂层。使用卡洛测试法确认涂层厚度。配备能量色散X射线光谱仪的扫描电子显微镜用于确定涂层的形态和元素组成。检查横截面样品以确定涂层厚度和附着力。使用X射线衍射仪进行结构分析。用纳米压痕仪测定仪器化纳米压痕硬度和弹性模量。评估纳米硬度与弹性模量的比值以观察涂层厚度对摩擦学行为的影响。
制备了三种涂层成分，即六方密排结构的锆、面心立方结构的氮化锆和面心立方结构的碳氮化锆。氮化锆涂层显示出最高的硬度和弹性模量，而纯锆涂层显示出最低的值。
发现所有涂层成分相对均匀、连续且附着性好，在涂层与基体界面处没有脱粘的迹象。本研究中制备的涂层被认为适用于摩擦学应用。
