Microstructural Development and Mechanical Properties of PM Ti–45Al–2Nb–2Mn–0.8 vol.%TiB2 Processed by Field Assisted Hot Pressing

Abstract

A -TiAl intermetallic alloy, Ti-45Al-2Nb-2Mn(at.%)-0.8vol.%TiB 2 , has been processed from gas atomized prealloyed powder by field assisted hot pressing (FAHP). An initial analysis of the prealloyed powder helped on the understanding of the intermetallic sintering behavior.Atomized powder consisted on  metastable phase that transformed into  2 + equilibrium phases by thermal treating. Different powder particle microstructures were found, which influence the microstructure development of the FAHP -TiAl material depending on the sintering temperature. Duplex, nearly lamellar and fully lamellar microstructures were obtained for the sintering temperatures above 1000 ºC. Lower consolidation temperatures, below 1000 o C, showed the formation of an Al rich phase at powder particle boundaries, which is

Effect of Zirconium on the Microstructure and Mechanical Properties of an Al‐Alloyed ODS Steel Consolidated by FAHP

“…Both MA ODS powders were consolidated by FAHP in a Gleeble 3800 apparatus developed by Dynamic System Inc. (Poestenkill, NY). Although the Gleeble 3800 is an equipment usually used for performing physical simulation and thermal‐mechanical materials testing, in this investigation it was used to sinter the ODS powders, as was recently reported by other authors . The FAHP technique involves the simultaneous application of pressure and a low‐frequency alternating current (AC).…”

“…Although the Gleeble 3800 is an equipment usually used for performing physical simulation and thermal-mechanical materials testing, in this investigation it was used to sinter the ODS powders, as was recently reported by other authors. 9,10 The FAHP technique involves the simultaneous application of pressure and a low-frequency alternating current (AC). Thus, the powders in the Gleeble system are heated by Joule effect (resistance heating) when an alternating current of 50 Hz is passed into the sample being consolidated through the system anvils.…”

Study and Suppression of the Microstructural Anisotropy Generated During the Consolidation of a Carbonyl Iron Powder by Field-Assisted Hot Pressing

“…[6][7][8] In this framework, the field-assisted hot pressing (FAHP) technique is situated, in which a high densification is performed by the simultaneous application of an uniaxial pressure and a low voltage and high alternate current to the sample. [9,10] This method produces a fast generation of internal heat by Joule effect and accelerates the diffusion among iron atoms, which increases the kinetics of sintering. [11,12] The heating rate and the obtained densification are high, leading to the final consolidated sample in around 20 minutes.…”

The effect of zirconium addition on sintering behaviour, microstructure and creep resistance of the powder metallurgy processed alloy Ti–45Al–5Nb–0.2B–0.2C

“…Pores can change the stress distribution around them leading to localized stress concentration, which induce cracking [39] and in turn might decrease the value of hardness. In case of powder metallurgy processed materials, there is typically residual porosity after sintering, even for processes such as Field Assisted Hot Pressing [40] or Cold Isostatic Pressing [41]. Additionally, there is an inverse correlation of porosity and hardness [42,43].…”