Refractory metals are extracted from ore concentrates or scrap, processed into intermediate chemicals, and then reduced to metal, usually in powder form. This article discusses the raw materials needed and the processing steps for producing pure and alloyed refractory metal powders. The effects of processing conditions on the physical and chemical properties of tungsten, molybdenum, tantalum, niobium, and rhenium powders are reviewed.

This article focuses on the forging characteristics of different types of refractory metals and alloys, namely, niobium and niobium alloys, molybdenum and molybdenum alloys, tantalum and tantalum alloys, and tungsten and tungsten alloys.

The melting temperature necessary to weld materials in the gas-tungsten arc welding (GTAW) process is obtained by maintaining an arc between a tungsten alloy electrode and a workpiece. This article discusses the advantages and limitations and applications of the GTAW process. It schematically illustrates the key components of a GTAW manual torch. The article describes the process parameters, such as welding current, shielding gases, and filler metal. It discusses the GTAW process variations in terms of manual welding, mechanized welding, narrow groove welding, and automatic welding.

This article describes various procedures used in the metallographic preparation of niobium, tantalum, molybdenum, and tungsten alloys. It provides information on sectioning, grinding, mounting, polishing, and electrolytic etching as well as alternate procedures that have been used on refractory metals. The article presents and analyzes several micrographs, provides etchant formulas for various materials, and discusses the unique characteristics of rhenium and its alloys.

This article is a compilation of binary alloy phase diagrams for which tungsten (W) is the first named element in the binary pair. The diagrams are presented with element compositions in weight percent. The atomic percent compositions are given in a secondary scale. For each binary system, a table of crystallographic data is provided that includes the composition, Pearson symbol, space group, and prototype for each phase.

The refractory metals include niobium, tantalum, molybdenum, tungsten, and rhenium. They are readily degraded by oxidizing environments at moderately low temperatures. Protective coating systems have been developed, mostly for niobium alloys, to permit their use in high-temperature oxidizing aerospace applications. This article discusses the properties, processing, applications, and classes of refractory metals and its alloys, namely molybdenum, tungsten, niobium, tantalum and rhenium. It also provides an outline of the coating processes used to improve their oxidation resistance.

This article focuses on the selection, properties, and applications of powder metallurgy refractory metals and their alloys, including tungsten, molybdenum, tantalum, niobium, and rhenium.

This article briefly discusses the annealing practices for refractory metals such as tungsten, molybdenum, niobium, tantalum, and rhenium and their alloys. It also presents the applications and properties of these metals and their alloys.

This article describes various machining techniques of refractory metals, namely, niobium, molybdenum, tantalum, and tungsten. These include turning, boring, trepanning, reaming, milling, tapping, drilling, and sawing. Parameters for the machining of the refractory metals are also tabulated. In addition, the article provides information on cutting fluids and tools that are used in machining of the refractory metals as well as on the safety precautions to be followed in the machining process.