报告题目：高温超硬薄膜的设计，沉积和表征

Design, deposition and characterization of nano-structured super-hard coatings for high temperature applications

报 告 人：刘世宇 (Singapore Institute of Manufacturing Technology)

时 间：2017年11月12日上午9:00

地 点：物理学院新楼5楼多功能厅

报告简介：

There has been an increasing demand for protective coatings with high temperature compatibility, especially for applications at extreme conditions, such as tools for high speed dry machining and turbine blades of jet engines, in which the thermal stability and oxidation resistance are key to the coating’s performance, in addition to the high hardness and toughness that are usually required. The aim of this talk is to address three main challenges associated with the development of such high temperature protective coatings: i.e., coating design, deposition, and characterization.

In the first part of the talk, the design and deposition of nano-structured CrAlSiYN coating systems will be presented, with the effects of Y doping on the coating microstructure, mechanical properties and oxidation kinetics investigated and explained. A novel strategy of introducing AlSiN intermediate layers to the bulk CrAlSiYN coatings will also be presented, which has led to significant and concurrent enhancement in both high temperature thermal stability and oxidation resistance, as the presence of AlSiN layers were found to effectively suppress diffusion processes both within the coating and at its interface with air and the substrate.

The second part of the talk will be devoted to a series of in-situ testing techniques developed to provide accurate and reliable characterization of the coatings deformation, fracture and delamination behaviours at the micro- and nano-metre scale. To demonstrate their effectiveness, these techniques, including elevated temperature micropillar compression for the investigation of coating deformation mechanism, micro double cantilever beam (DCB) compression to evaluate coating fracture toughness, and single cantilever beam compression for the characterization of coating delamination, will be demonstrated on a series of CrAlSiN nanocomposite coatings, with the results discussed and interpreted to guide future development of hard protective coatings.

邀请人：王建波教授