Microstructure, Wear Resistance and Oxidation Behavior of Ni-Ti-Si Coatings Fabricated on Ti6Al4V by Laser Cladding

Abstract

The Ni-Ti-Si composite coatings were successfully fabricated on Ti6Al4V by laser cladding. The microstructure were studied by SEM (scanning electron microscopy) and EDS (energy dispersive spectrometer). It has been found that Ti2Ni and Ti5Si3 phases exist in all coatings, and some samples have TiSi2 phases. Moreover, due to the existence of these phases, coatings presented relatively higher microhardness than that of the substrate (826 HV (Vickers hardness)) and the microhardness value of coating 3 is about twice larger than that of the substrate. During the dry sliding friction and wear test, due to the distribution of the relatively ductile phase of Ti2Ni and reinforcement phases of Ti5Si3 and TiSi2, the coatings performed good wear resistance. The oxidation process contains two stages: the rapid oxidation and slow oxidation by high temperature oxidation test at 800 °C for 50 h. Meanwhile, the value of the oxidation weight gain of the substrate is approximately three times larger than that of the coating 4. During the oxidation process, the oxidation film formed on the coating is mainly consisted of TiO2, Al2O3 and SiO2. Phases Ti2Ni, Ti5Si3, TiSi2 and TiSi were still found and it could be responsible for the improvement in oxidation resistance of the coatings by laser cladding.

Microstructure, Wear Behavior and Corrosion Resistance of WC-FeCrAl and WC-WB-Co Coatings

“…For WC-FeCrAl and WC-WB-Co coatings, comparative studies are missing; however for conventional WC-Co coatings, there is a large amount of relevant literature [1][2][3][4][5]7,12,15,[20][21][22][23][24]. Therefore, a team of authors, Bolelli et al [25][26][27][28], decided to elaborate with a detailed comparative study focused on the microstructure, micromechanical properties, residual stresses, and wear of the WC-FeCrAl coating in comparison with the conventional WC-CoCr coating.…”

Fabrication and Anti-Oxidation Ability of SiC-SiO2 Coated Carbon Fibers Using Sol-Gel Method

“…It can prevent CF substrate from contacting the oxygen directly. The type of coating can be various, such as metal coating (Zn, Ni, Cu, Ti, Zr, Ag); oxides coating (SiO 2 , Fe 3 O 4 , Al 2 O 3 , TiO 2 ), nitrides coating (BN, TiN), carbides coating (SiC, TiC, TaC, ZrC, B 4 C), and composite coating (Al 2 O 3 /Y 2 O 3 , ZrC–ZrB 2 –SiC, SiBNC) [5,6,7,8,9,10,11,12,13,14,15,16]. Among them, ceramic coatings are the most promising coatings due to the fact that they are much lighter and have better wettability, which can reduce interface diffusion and reaction.…”

Fabrication of High Temperature Oxidation Resistance Nanocomposite Coatings on PEO Treated TC21 Alloy

“…However, its widespread application in high temperature parts of the aircraft are still limited due to poor high temperature oxidation resistance. To date, various coating methods have been studied to improve the high temperature oxidation resistance, including electron-beam physical vapor deposition [6], plasma spraying [7], hot dipping [8], laser cladding [9], arc ion plating [10], magnetron sputtering [11], sol-gel [12], and plasma electrolytic oxidation (PEO) [13].…”