ABSTRACT

The present work is concentrated on the erosive behaviour of NiCrAlY/B₄C/Cenosphere composite coating at high temperatures. The coating was deposited on MDN 321 steel used in turbine blades by plasma spray coating technique. The erosion tests were carried out at impingement angles of 60° and 90° with temperature at 600°C in both cases. The coatings and worn samples were characterised by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Al₂O₃ particles of 150 microns were used as the erodents with a velocity of 30 m s⁻¹. The erosive wear resistance for the impingement angle of 60° was found to be higher compared to 90°. The major failure of the material is shown by the brittle nature of the material removal. This is also reflected by the higher particles size found around the eroded area and higher surface roughness values of Ra and Rz.

摘要

目前的工作集中在 NiCrAlY/B ₄ C/Cenosphere 复合涂层在高温下的侵蚀行为。该涂层通过等离子喷涂技术沉积在用于涡轮叶片的 MDN 321 钢上。在两种情况下，侵蚀试验均在 60° 和 90° 的冲击角和 600°C 的温度下进行。通过扫描电子显微镜 (SEM) 和能量色散光谱 (EDS) 对涂层和磨损样品进行了表征。使用 150 微米的Al ₂ O ₃颗粒作为侵蚀剂，速度为 30 ms ^-1. 与 90° 相比，发现 60° 冲击角的耐冲蚀磨损性更高。材料的主要失效表现为材料去除的脆性。这也反映在侵蚀区域周围发现的较高颗粒尺寸和较高的 Ra 和 Rz 表面粗糙度值。