Heat Treatment, Impact Properties, and Fracture Behaviour of Ti-6Al-4V Alloy Produced by Powder Compact Extrusion.

Singh Singh,Gabbitas Gabbitas,Yang Yang,Torrens Torrens

doi:10.3390/ma12233824

Abstract

The mechanical properties of titanium and titanium alloys are very sensitive to processing, microstructure, and impurity levels. In this paper, a blended powder mixture of Ti-6Al-4V alloy was consolidated by powder compact extrusion that involved warm compaction, vacuum sintering, and hot extrusion. The as-processed material with an oxygen content of 0.34 wt.% was subjected to various annealing treatments. The impact toughness of heat-treated material was determined using Charpy V-notch impact testing at room temperature. An emphasis was placed on establishing a relationship among fracture behaviour, microstructure, and the resulting properties of tested material. From the results, it is apparent that the highest impact toughness value of 19.3 J was achieved after α/β annealing and is comparable with typical values given in the literature for wrought Ti-6Al-4V. In terms of fracture behaviour, it is quite apparent that the crack propagation behaviour of powder-produced material is rather complex compared with the limited amount of data reported for ingot counterparts.

Highlights

The microstructures in material produced by powder metallurgy (PM) tend to be more complex than ingot-derived material, with more refined features
The theme of this paper is to evaluate the effect of various heat treatments on material produced by powder compact extrusion (PCE) processing
The chemical composition and oxygen content of the material after various heat treatments are shown in Table 2 along with as-processed material (VS-E3’)

Summary

Introduction

The microstructures in material produced by powder metallurgy (PM) tend to be more complex than ingot-derived material, with more refined features. Heat treatment of such microstructures results in more diversity in terms of grain and α/β colony size and the morphology of both lamellar and grain boundary α. Finding a possible relationship among heat treatment, resulting microstructure, and mechanical properties is rather important in powder-produced material. If relatively inexpensive powders are being used, titanium and titanium alloys produced by PM route have much higher impurity contents compared to ingot counterparts. It is very important to determine the level of enhancement or balance of properties that can be obtained from various heat treatments. The theme of this paper is to evaluate the effect of various heat treatments on material produced by powder compact extrusion (PCE) processing

Methods

Results

Discussion

Conclusion