Powder Metallurgy Strategies to Improve Properties and Processing of Titanium Alloys: A Review

Abstract

Powder metallurgy (PM) is an attractive technology for manufacturing net-shape titanium-based components. However, it is challenging to make PM titanium products competitive in terms of mechanical properties. This article gives an overview of the current challenges in PM titanium and the best strategies to overcome them by alloying. By adding suitable alloying elements the properties of PM titanium components can be enhanced. The use of sintering aids helps to control the typical residual porosity of PM titanium alloys. Furthermore, controlling microstructure by alloying offers the possibility to go for high performance applications. Moreover, ductility is improved by adding elements that scavenge oxygen. A favorable selection of alloying elements offers a practical and competitive approach to meet the mechanical requirements in future PM titanium applications.

Beta Titanium Alloys Produced from Titanium Hydride: Effect of Alloying Elements on Titanium Hydride Decomposition

“…Aerospace and biomedical are currently the most important fields for applications of titanium products. Ti-based components are typically manufactured by a multi-step process of vacuum arc melting, hot rolling, scale removal, vacuum annealing machining, and surface treatment; all these fabrication stages make the final product expensive [1][2][3]. Powder metallurgy (PM) processing offers an interesting alternative for many applications since it provides near-net-shape parts [1], enhancing the flexibility of design, minimizing the machining steps, and increasing the material yield.…”

“…On the other hand, processing of titanium powders to give final components by the conventional pressing and sintering route requires sintering temperatures around 1200-1400 • C employing long dwell times (2 to 5 h typically) which suppose high energy consumption. Hence, there is room to reduce processing cost by means of alternative routes or using alternative starting powders and alloying elements that help to improve the sintering parameters maintaining the final properties, in terms of density and microstructure [1,8].…”

Microstructure and Properties of Porous Titanium Prepared by Spark Plasma Sintering

“…Figure 1 is the original titanium powder morphology, and Table 1 is the powder composition. Metal powder is the key raw material for powder metallurgy, and its quality largely determine the final moulding effect and comprehensive performance of powder metallurgy products [20]. The apparent density and flowability of the original Ti powder were tested by Hall flow-meter.…”

Predicting Workability of a Low-Cost Powder Metallurgical Ti–5Al–2Fe–3Mo Alloy Using Constitutive Modeling and Processing Map

“…Then, the predicted value of flow stress (σp) could be obtained by Equation (13). The value of Z could be calculated by Equation (10):…”

“…Some researchers consider Fe a promising substitution for V in α + β titanium alloys due to its relatively low cost and strong BCC phase stablishing ability [ 8 , 9 ]. It was reported that the addition of Fe could also help to enhance the sinterability of PM titanium components, thanks to its high diffusion rate in Ti [ 10 , 11 , 12 ]. On the other hand, the local segregation of Fe particles and the formation of a brittle TiFe phase could be prevented in the solid sintering process [ 13 ].…”