Abstract
Ti6Al4V, an aerospace alloy, is the most widely
produced titanium alloy because of its exciting properties such
as high strength to weight ratio and excellent corrosion
resistance properties. Despite these properties of this titanium
alloy, the wear property is poor because of its chemical
property that makes it react with other material it comes in
contact with. Therefore, there is need for surface modification
of the titanium alloy if it will be used in application where it
will come in contact will other material in rubbing or sliding
action. TiC has been used to improve the wear resistance
property of titanium alloy with success. Laser metal deposition
(LMD) process, an additive manufacturing process, is an
advanced manufacturing process for achieving part with the
desired surface property as well as for producing complex part
directly from the three dimensional (3D) computer aided
design (CAD) model of the part. Processing parameter has a
great influence on the resulting properties of the deposited part
using LMD. This research investigates the influence of laser
power and scanning speed on the in-situ formation of titanium
aluminide (Ti3Al) during laser metal deposition of
TiC/Ti6Al4V composite and its overall effect on the wear
resistance behaviour of the deposited composites. The laser
power was changed between 1.8 and 3.0 kW and the scanning
speed was changed between 0.05 and 0.1 m/s. It was found that,
the intermetallic produced increased as the scanning speed was
reduced from 0.1 to 0.05 m/s. The intermetallic formed at low
scanning speed was found to decrease as the laser power was
increased from 1.8 to 3.0 kW, while it was found to increase as
the laser power was increased at higher scanning speed. The
wear resistance property increases as the intermetallic
formation increases. This study revealed that finding an
optimum process parameter is important in achieving better
properties in laser metal deposition of TiC/Ti6Al4V composite.
The optimum process parameter was found to be at laser
power of 1.8 kW and scanning speed of 0.05 m/s based on the
process parameters considered in this study.