Effect of Dilution and Cooling Rate on Hardness in Laser Metal Deposition of Ti-۶Al-۴V

Laser metal deposition of Ti-۶Al-۴V is conducted on acommercially pure titanium grade ۲ substrate withdifferent processing conditions. The dilution, grain size,and microhardness of the tracks are measured asimportant properties of the deposited material. Dilutionand cooling rate are studied as the two mechanismsaffecting the deposition hardness. Increased dilutionresults in lower hardness while a higher cooling rateresults in a higher hardness. Laser power and wire feedingrate are examined as two controlling parameters fordilution and cooling rate. A higher laser power leads toincreased dilution and decreased cooling rate. In contrast,a higher wire feeding rate decreases dilution and increasesthe cooling rate. Results show that deposition dilution hasthe main role in defining the hardness during laser metaldeposition of Ti-۶Al-۴V.

Keywords:

Laser Metal Deposition , Ti-۶Al-۴V , Dilution , Cooling Rate , Grain Size , Hardness