Characterization of Prealloyed Ti–6Al–4V Powders from EIGA and PREP Process and Mechanical Properties of HIPed Powder Compacts

Abstract

Prealloyed Ti-6Al-4V powders were prepared by electrode induction melting gas atomization (EIGA) and plasma rotating electrode process (PREP) in this work. A comparative study of EIGA and PREP powders for hot isostatic pressing (HIPing) compaction was conducted. Characterization of important technological parameters such as particle size distribution, powder surface morphology and flowability was carried out. Microstructure and mechanical properties of Ti-6Al-4V powder compacts HIPed from EIGA and PREP powders were also investigated. The results showed that the EIGA powder has a finer average particle size and higher tap density, while the PREP powder has better flowability and less pores. Micropores can be observed in heat-treated EIGA powder compacts by X-ray tomography and the porosity was found to be about 0.02%. There are no micropores (C4 lm) to be detected in heat-treated PREP powder compacts. Transgranular fracture mode as well as micropores contributes to the scatter in fatigue property of heat-treated PREP powder compacts. The respective advantages and disadvantages of both EIGA and PREP powders for producing Ti-based complex parts through HIPing were also discussed.

Microstructure and mechanical properties of Titanium grade 23 produced by selective laser melting

“…On the other hand, ductile fracture was found in Ti-6Al-4V alloy produced by the electron beam and laser melting ( [83] and [77], respectively). Predominantly ductile fracture was usually observed in wrought Ti-6Al-4V [84] and [85], and in the hot isostatic pressed one [74], and a brittle failure mechanism was identified only locally [86]. A similar mixed type of fracture surface was observed by Pang et al for SLM alloy Ti-6Al-4V [87].…”

“…So, strength was higher and ductility lower compared to typical materials: to SLM Titanium grade 23 (produced by 3D Systems Co.) subjected to stress relief annealing (i.e. YS = 970 ± 30 − 1100 ± 60 MPa, UTS = 1070 ± 30-1170 ± 50 MPa, El = 10 ± 3-13 ± 3%) [25], to Ti-6Al-4V alloy produced by the classical powder metallurgy route (YS = 840-890 MPa, El = 17-19% [74]) and to commercial grades (e.g., AZO Materials portal [27], and The METALCOLOR one [75]). However, the ductility of Fig.…”

A Study on Internal Defects of PREP Metallic Powders by Using X-ray Computed Tomography

“…The reason for the difference in the number proportions of powder with pores is mainly attributed to the surface tension and density of the alloy. Under the ligament disintegration (LD) mechanism, the mean particle size can be calculated by [ 28 , 29 ] where is the surface tension, is rotation speed, is density and D is electrode diameter. When the rotation speed and diameter of electrode bar are determined, the average particle size depends on the density and surface tension of the alloy.…”

Comportement à l’usure et au frottement de deux biomatériaux AISI 316L et Ti-6Al-7Nb pour prothèse totale de hanche

“…Pour les aires de contact élevées, les résultats obtenus montrent que le coefficient de frottement est indépendant de la charge normale. En revanche, pour les très petites aires de contact, le coefficient de frottement augmente en fonction de la force normale [35,36]. La valeur de ce critère donne une estimation grossière de la différence à la résistance et à la déformation plastique entre les deux matériaux [37].…”