Distinguishing the influence of aluminium and vanadium additions on microstructural evolution and densification behaviour during the sintering of ti6Al, ti4V and ti6al4v

ABSTRACT

In this work, the influence of pure Al (Ti6Al) and V (Ti4 V) powder additions on the sintering behaviour of a coarse CP-Ti powder compact was investigated. Pure Al melts and spreads to form intermetallic layers at the CP-Ti surface, causing swelling and prevention of sintering and shrinkage below 1050°C. Ti4 V compacts do not swell and begin to sinter at 990°C. The sinter rate for both Ti4 V and Ti6Al are similar at 1200°C and higher than the CP-Ti compact alone. Aluminium melting distributes this element better than the dispersed V particles, leading to more rapid homogenisation. When both pure Al and V are present (Ti6Al4 V), the sintering rate at 1200°C is similar to that of Ti6Al and Ti4 V. However, swelling is increased and homogenisation is slower, resulting in a reduced sintering aid effect compared to Ti6Al and Ti4 V.

KEYWORDS:

• Powder metallurgy
• blended elemental
• sintering
• titanium
• differential scanning calorimetry (DSC)
• dilatometry

Acknowledgements

We acknowledge the efforts of Timmy Sarker for his contributions towards some of dilatometry work reported in this paper.

Notes on contributors

G. Steedman has an MASc in Materials Enginnering from Dalhousie University and now has a position at Canadian Nuclear Safty Commission.

S.F. Corbin has a PhD in Materials Engineering from McMaster University and now has a position as Professor at Dalhousie University.

J. O’Flynn has an MASc in Mechanical Engineering from the McGill University and now has a position as a Research Associate at Dalhousie University.

Additional information

Funding

The authors would like to thank the Natural Sciences and Engineering Research Council of Canada and its Automotive Partnership Canada programme for their financial support of this research. They would also like to thank Wescast Industries Inc. and Kingston Process Metallurgy Inc. for their financial, in-kind and technical support. Funding from NSERC through their Automotive Partnerships (APC) program is acknowledged.