MATERIALS CHALLENGES TO HIGH TEMPERATURE MARINE ENVIRONMENTS

摘要

High temperature applications demand materials that have a variety of properties such as high strength, toughness, creep resistance, fatigue resistance, as well as resistance to environmental degradation. All potential alloys tend to become unstable in many high temperatures environments, particularly in the salt-laden marine environment, without the presence of a stable, protective coating on the component surface. Reliable high temperature propulsion materials are critical for enabling improvements in engine efficiency, reducing fuel costs, and decreasing maintenance/total life cycle costs. Propulsion materials for both Naval aircraft and ship gas turbine engines are subjected to the corrosive environment of the sea to differing degrees. Materials life is dependent on dynamic combinations of many inherent factors such as temperature, environment, and stress and need to be to be resistant to oxidation, corrosion, or alternating cycles of oxidation and corrosion. Research seeks to explore and understand the thermodynamics and kinetics of materials interactions and materials stability in Naval environments and temperatures in order to develop models that lead to creating new materials or establishing life prediction capabilities for existing and novel materials. Research seeking to discover new mechanisms and causes that lead to materials instabilities and degradation should also explore how these mechanisms fundamentally relate to mechanics, interdiffusion, coating or material chemistry, temperature, environment, and structure in order to establish fundamental scientific principles to mitigate such instabilities and degradation. This paper will dwell on some past results of materials testing and offer some views on future directions into materials research in high temperature materials in aggressive Naval environments which can be applicable to other high temperature applications.