Critical assessment 4: Challenges in developing high temperature materials

Materials are a key enabling feature for high efficiency engines for power generation or transportation. While significant research continues, progress in this century has certainly slowed compared to the previous century where modern materials science spawned a rapid advance in high temperature materials. One area that hampers new high temperature materials is a lack of inherent (i.e. uncoated) oxidation or environmental resistance, especially for the highest temperature applications such as Ni-base superalloys for turbomachinery. Thus, there appears to be more opportunity to develop materials for 600–1000°C applications than for higher temperatures. New materials requirements ranging from mechanical and environmental resistance to manufacturing and joining need to be clearly defined and experimental work focused on validating these properties for successful alloy development to proceed. For most applications the materials requirements have become so broad and complex that progress by single researchers is difficult. A teaming approach, especially among research institutions and industry, is needed to both define the critical needs and assemble experts in a range of disciplines to address these issues during the materials development process.