Abstract
Abstract
Advanced film cooling technologies for hot gas path components in gas turbine engines with still constantly increasing inlet temperatures require special manufacturing processes. Today, laser radiation is the preferred means of drilling a large number of small-diameter cooling holes in turbine parts made of nickel-base superalloys. Most of these materials, however, exhibit a relatively high susceptibility to hot cracking in the heat affected zone (HAZ) adjacent to the recast layer. Comprehensive metallographical examinations have been performed to optimise laser drilling parameter settings to minimize hot cracks. In the case of René 80, there seems to be a pronounced microstructural influence on hot cracking sensitivity, i.e. identical laser parameters may produce quite different crack lengths, dependent upon local microstructure in the immediate vicinity of the drilled hole. Grain size, grain boundary morphology and orientation, and primary carbide distribution apparently have a significant influence. These interdependencies should be taken into account when acceptable crack lengths are specified. As far as conventionally investment cast components are concerned, influencing local microstructural features with economically viable effort may be unrealistic.
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science
Cited by
19 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献