Product Code: ICAL05_607

Microstructure Study of Direct Laser Fabricated Compositionally Graded Ti Alloys Using Simultaneous Feed of Powder and Wire
Authors:
Xinhua Wu, The University of Birmingham; Birmingham UK
Fude Wang, The University of Birmingham; Birmingham UK
Junfa Mei, The University of Birmingham; Birmingham UK
Presented at ICALEO 2005

A compositionally graded material has been fabricated using Direct Laser Fabrication technology. A burning resistant alloy Ti-25V-15Cr-2Al-0.2C powder and a Ti-6Al-4V wire are used in this study. Two types of feedstock were fed simultaneously into the laser focal point with the mixing ratio varying from the bottom to top of the samples to achieve compositionally graded materials. The compositionally graded samples using such feedstock have been successfully fabricated. The composition of the graded samples along the height of a sample was measured using EDX and the microstructure and grain size were assessed using image analysis. The change of phase and lattice parameter with the change of composition has been examined by X-ray and TEM. It has found that with gradual increase of the feed speed of the burning resistant alloy powder whist the feed rate of Ti-6Al-4V wire is kept constant primary beta grain size and the lattice parameter of the beta phase both decreases continuously. Some mechanical properties of such materials will also be reported.