Consolidation of titanium powders at room temperature may be performed by low-cost conventional powder metallurgy processes. This article provides information on various consolidation methods, namely, die pressing, direct powder rolling, and cold isostatic pressing. It also describes the sintering of blended elemental powders, high-strength titanium alloys, and porous material as well as the sintering of titanium powders by microwave heating.

This article is a comprehensive collection of properties, compositions, and applications of standard grades of titanium and selected titanium alloys. It provides data regarding the common names, Unified Number System numbers, composition limits, typical uses with service temperatures, precautions in use, and general corrosion behavior of each. The applications of titanium alloys include aerospace, gas turbine engines and prostheses. Further, the article graphically presents a comparative study of fatigue, creep and tensile properties of various titanium alloys.

Titanium and its alloys are used in various applications owing to its high strength, stiffness, good toughness, low density, and good corrosion resistance. This article discusses the applications of titanium and titanium alloys in gas turbine engine components, aerospace pressure vessels, optic-system support structures, prosthetic devices, and applications requiring corrosion resistance and high strength. It explains the effects of alloying elements in titanium alloys as they play an important role in controlling the microstructure and properties and describes the secondary phases and martensitic transformations formed in titanium alloy systems. Information on commercial and semicommercial grades and alloys of titanium is tabulated. The article also discusses the different grades of titanium alloys such as alpha, near-alpha alloys, alpha-beta alloys, beta alloys, and advanced titanium alloys (titanium-matrix composites and titanium aluminides).

Direct powder rolling (DPR) is a process by which a suitable powder or mixture of powders is compacted under the opposing forces of a pair of rolling mill rolls to form a continuous green strip that is further densified and strengthened by sintering and rerolling. This article discusses the basic principle, process considerations, and advantages of DRP, and describes the application of this process in the manufacture of powder titanium and titanium alloy components. It further illustrates the complexity of the process and describes the benefits of using DRP in terms of economics and product quality.

This article focuses on mechanical testing characterization of blended elemental powder metallurgy (PM) titanium alloys and prealloyed PM titanium alloys. It examines the tensile properties, fracture toughness, stress-corrosion threshold resistance, fatigue strength, crack propagation properties, and processing-microstructure-property relationships of these alloys. The article also reviews five considerations for powder process selection.

This article focuses on the mechanical properties, production of titanium powder metallurgy (P/M) compacts, namely, blended elemental (BE) compacts and prealloyed (PA) compacts. It explains the postcompaction treatments of titanium P/M compacts, including heat treatment, and thermochemical processing. The article talks about the applications of titanium P/M products, namely, BE and PA products. It concludes with a short note on the future trends in titanium P/M technology.

This article summarizes the metallurgical and environmental variables that affect fracture toughness, fatigue life, and subcritical crack growth of titanium alloys, such as chemistry, microstructure, texture, environment, and loading. The classes of titanium alloys considered in the article include alpha-beta alloys, Ti-6AI-4V; alpha alloys, Ti-8Al -1Mo-IV, Ti-5AI-2.5Sn, Ti-6242S; and beta alloys, solute-lean beta alloys and solute-rich beta alloys.

This article focuses on the physical metallurgy and weldability of four families of titanium-base alloys, namely, near-alpha alloy, alpha-beta alloy, near-beta, or metastable-beta alloy, and titanium based intermetallics that include alpha-2, gamma, and orthorhombic systems.

This article emphasizes the physical metallurgy of titanium and titanium alloys along with their microstructural response to fusion welding condition. The titanium alloys are classified into unalloyed or commercially pure titanium, alpha and near-alpha alloys, alpha-beta alloys, and metastable beta alloys. The article further discusses the weld microstructure for alpha-beta and metastable beta alloys and describes welding defects observed in titanium alloys. The influence of macro- and microstructural characteristics of titanium weldment on mechanical properties is also discussed. The article concludes with a discussion on the different welding processes used in the welding of titanium and titanium alloys.

This article introduces the different types, distinctions, and grades of commercially pure titanium and titanium alloys. It describes three types of alloying elements: alpha stabilizers, beta stabilizers, and neutral additions. The article discusses the basic categories of titanium alloys, namely, alpha and near-alpha titanium alloys, beta and near-beta titanium alloys, and alpha-beta titanium alloys. It also describes the general microstructural features of titanium alloys.

This article discusses the wrought product forms of titanium and titanium-base alloys, which include forgings and the typical mill products with tabulations for various specifications, and compares specifications for pure titanium, titanium alloys for mechanical, physical properties and chemical properties, including chemical composition, corrosion resistance, and chemical reactivity. The article discusses the effects of alloying elements in titanium alloys, and describes the classes of titanium alloys, namely, alpha alloys, alpha-beta alloys, and beta alloys. It also describes the typical applications of various titanium-base materials, and explains the crystal structure, effect of impurities, and microstructural constituents of titanium alloys. The article provides a brief description on the processing of wrought titanium alloys, including primary fabrication in which ingots are converted into general mill products and secondary fabrication (forging, extrusion, forming, machining, chemical milling and joining) of finished shapes from mill products and the heat treatment of titanium alloys.

This article provides an in-depth treatment on the deformation and recrystallization of titanium alloys. It provides information on the predominant mode of plastic deformation that occurs in titanium in terms of the most common crystallographic planes. The article explains the relationship of the recovery process to the recrystallization, grain-growth process, and the effects of time and temperature on stress relief. It describes the factors that influence the rate of recrystallization and the conditions required for neocrystallization to occur. The article explains the mechanism of strain hardening and its effects on the mechanical properties of titanium alloys. It also discusses the factors that influence the superplasticity of titanium alloys.

The response of titanium and titanium alloys to heat treatment depends on the composition of the metal, the effects of the alloying elements on the alpha-beta crystal transformation, and the thermomechanical processing utilized during processing of the alloy. This article provides a detailed discussion on the effects of heat treatment on the mechanical properties for three general classes of titanium alloys, namely, alpha and near-alpha titanium alloys, alpha-beta alloys, and beta alloys.

Prealloyed (PA) powder metallurgy is a technique where complex near-net shape titanium aircraft components are fabricated with low buy-to-fly ratios. This article describes the physical principle, mechanism, and simulation and modeling of metal can and hot isostatic pressing (HIP) processes involved in the PA powder metallurgy technique. It discusses the technical problems addressed in shape control and their solutions for understanding the advantages of powder metallurgy HIP.

Metallic matrices are essential constituents for the fabrication of metal-matrix composites (MMCs). This article describes three different classes of aluminum alloys, namely, commercial aluminum alloys, low-density and high-modulus alloys, and high temperature alloys. It presents typical tensile properties and fracture toughness of the selected heat treatable aluminum alloys in a table. Titanium alloys are very attractive for MMC applications, due to their higher strength and temperature capability compared to aluminum alloys. The article tabulates the effect of heat treatment on room-temperature properties and tensile properties of Ti-25Al-17Nb alloy sheet.

The warm and hot working of metals provide the ability to shape important materials into component shapes that are useful in a variety of applications requiring strength, toughness, and ductility. This article focuses on a variety of metals that can be hot or warm worked, and describes the characteristics and processing considerations of each metal. It discusses forging because it is a versatile metalworking process and performed at cold, warm, and hot working temperatures. The article also presents the applications of steels, stainless steels, aluminum alloys, titanium alloys, superalloys, and copper alloys.

Titanium metal passes through three major steps during processing from ore to finished product: reduction of titanium ore to sponge (porous form), melting of sponge and scrap to form ingot, and remelting and casting into finished shape. This article describes primary fabrication, including all operations that convert ingot into general mill products, such as billet, bar, plate, sheet, strip, tube, and wire. The section on secondary fabrication describes processes such as die forging, extrusion, hot and cold forming, machining, chemical milling, and joining. The article presents a short note on powder metallurgy products of titanium. Casting processes and properties are covered in the final section.

Titanium and its alloys have been used extensively in a wide variety of implant applications, such as artificial heart pumps, pacemaker cases, heart valve parts, and load-bearing bone or hip joint replacements or bone splints. This article discusses the properties of titanium and its alloys and presents a list of titanium-base biomaterials. Titanium components are produced in wrought, cast, and powder metallurgy (PM) form. The article describes forging, casting, and heat treating of titanium alloys for producing titanium components. Typical mechanical properties of titanium biomedical implant alloys are listed in a tabular form. The article presents an overview of the surface-modification methods for titanium and its alloys implants. It concludes with a section on biocompatibility and in vivo corrosion of titanium alloys.

Quenching is a widely used technique to strengthen titanium alloys. This article presents the metallurgical and structural background underlying the specific techniques applied in the quenching of various titanium alloys, and the ways to control and reduce residual stresses induced from quenching or other thermal or mechanical processes. It discusses the types and microstructures of titanium alloys, namely, alpha, alpha-beta, and beta alloys, and describes the general effects of the various heat treatments. The article provides information on quenching media, quenching rate, section size, and martensitic transformation in quenched titanium alloys. It shows how residual stresses in titanium alloys are evaluated and controlled. Finally, the article describes the stress-relief treatments used to reduce residual stresses.