Development and application of titanium alloy casting technology in China
The development and research of titanium cast alloy and its casting technology, especially its application in aeronautical industry in China are presented. The technology of molding, melting and casting of titanium alloy, casting quality control are introduced. The existing problems and development trend in titanium alloy casting technology are also discussed.
The future use of gamma titanium aluminides by Rolls‐Royce
Gamma titanium aluminide is a material essential for meeting military and civil engine performance targets in the future and potentially it could be used throughout the engine from compressor to combustor to turbine. The current alloy being used within Rolls‐Royce is the established Ti‐45‐2‐2‐XD. This is competing for lower temperature applications such as stators and structural components which take advantage of the lower costs arising from the casting route. Rigorous design criteria are required to compensate for the risks in using these relatively new materials in components and this requires investigation into the effects of manufactured surface conditions, of microstructures local to load bearing regions and of compositional variations. For the future, Rolls‐Royce has patented a next generation gamma titanium resulting from alloy development programmes undertaken by the University of Birmingham. The aim is to optimise castability with strength and creep resistance and their potential for commercial use within the aero‐engine is discussed.
Nursing theory and administrative practice: Agenda for the 1990s
&NA; Despite past progress in the development of nursing theory, a theoretical nursing perspective is not yet common to the practice of nursing administration. Such a perspective could serve as a catalyst both to advance knowledge development for administrative nursing practice and to align clinical and administrative practice within a common framework. In this article assumptions, concepts, and questions common to both clinical and administrative nursing practice are identified. Select domain concepts are used to exemplify the themes shared by nurse clinicians and nurse administrators. The article concludes with a five‐item agenda as a guide for future theory development.