Search Results for 2.5Ni-Cr-Mo

High-temperature sintering of ferrous components continues to be important in the powder metallurgy (PM) industry. Improvements in both production rates and properties are possible as sintering temperatures increase above 1120 deg C. This article provides an overview of the different various stages of the sintering process and the physical, chemical, and metallurgical phenomena occur within the mass of metal powder particles. It discusses the four advantages of high-temperature sintering of various ferrous PM materials: improved mechanical properties, improved physical properties, development of liquid phase, and ability to sinter active elements in alloy steels. The article also provides information on three sources of process control requirements, namely, the powder blend, green density, and sintering conditions.

Martensite is a metastable structure that forms during athermal (nonisothermal) conditions. This article reviews the crystallographic theory, morphologies, orientation relationships, habit plane, and transformation temperature of ferrous martensite microstructures. It examines the stages of the tempering process involved in ferrous martensite. The article also describes the formation of the martensite structure in nonferrous systems. It concludes with a discussion on shape memory alloys.

The initial cast superalloy developments in the United States centered on cobalt-base materials. Nickel-base and nickel-iron-base superalloys owe their high-temperature strength potential to their gamma prime content. For polycrystalline superalloy components, high-temperature strength is affected by the condition of the grain boundaries and, in particular, the grain-boundary carbide morphology and distribution. Vacuum induction melting offers more control over alloy composition and homogeneity than all other vacuum melting processes. The primary purification reaction occurring in the process is the removal of melt contained oxygen by means of a reaction with carbon to form carbon monoxide. A number of casting processes can provide near-net shape superalloy cast parts, but essentially all components are produced by investment casting. The solidification of investment cast superalloy components is precisely controlled so that the microstructure, which ultimately determines mechanical properties, remains consistent. Heat treating cast superalloys involves homogenization and solution heat treatments or aging heat treatments.

This article is a compilation of property data for standard grades of cast aluminum alloys. Data are provided for mechanical, thermal, and electrical properties. The listing for each alloy includes commercial names, chemical compositions, applications, relevant specifications, fabrication characteristics, and mass characteristics.