Preparation and Analysis of Amorphous Gradient Composites on TC17 Titanium Alloy by Laser Melting Deposition (LMD)
Z-Y. Liu, J-N. Li, Y-W. Sui, P. Liu and K-G. Liu
Amorphous gradient composites were produced on a TC17 titanium alloy substrate by means of laser melting deposition (LMD) with a high power diode laser (HPDL). The bottom composites were Deloro50-Si3N4-Sb- La2O3 mixed powders and were deposited directly onto the substrate. They were found to have excellent toughness and wear resistance. The upper composites were Deloro50-Si3N4 mixed powders and were deposited directly onto the bottom composites. The test results showed that a good metallurgical bond was formed between the bottom and upper composites. Elements were seen to have entered into a laser meltpool from the TC17 titanium alloy substrate during LMD processing. These were identified as nanoparticles (NPs) and amorphous phases were produced in the composites under the actions of Sb and La2O3 which, in turn, improved the wear resistance of the surface of the TC17 titanium alloy.
Keywords: High power diode laser (HPDL), TC17 titanium alloy, mixed powder, laser melting deposition (LMD), amorphous phases, microstructure, wear resistance