Session: 02-10-01: Session #1: Robotics and Automation in Advanced Manufacturing

Paper Number: 96945

96945 - Microstructure and Mechanical Properties of Inconel 718 / Yttria-Stabilized Zirconia (YSZ) Metal Matrix Composite Coating Produced by Laser Directed Energy Deposition Technique 

Metal matrix composites (MMC) exhibit a variety of mechanical, thermal, physical and electrical properties which can be engineered by controlling concentration, size and dispersion of the ceramic particles. Laser direct energy deposition (DED) technique has ability to fabricate coatings with sound metallurgical bonding and has also well-known applications, like surface depositions, for improving or altering the corrosion and/or wear resistance of the material. The accuracy and precision of the laser DED process are high because of the controlled heat input and minimal dilution. With these beneficial aspects, laser cladding finds application in the development of a thermal barrier coating and it can overcome the shortcoming of other processes for manufacturing MMCs. Despite the tremendous potential of MMCs, there has been limited work reported in development of MMC layers. In the present study, inconel 718/yttria-stabilized zirconia (YSZ) metal matrix composite coating was deposited on the H13 steel substrate via laser DED process. A 3 kW ytterbium fiber laser system with 1.07 μm wavelength was employed in the continuous mode of operation and the deposition head was mounted on a six-axis KUKA robot. During laser processing, the entire processed zone was shielded with argon gas to eliminate the possibility of oxygen entrapment in the molten pool under the liquid state. A powder feeder was used to supply the powder to the deposition head at a specific feed rate. This MMC can find applications as ultra-high strength thermal barrier coatings in aerospace and die/mold applications. Three types of MMCs such as Inconel-1 wt.% YSZ, Inconel-2 wt.% YSZ, and Inconel-3 wt.% YSZ were fabricated in order to assess the effect of YSZ weight percentage on the microstructure and mechanical properties (i.e., micro-hardness and porosity) of the MMC. Moreover, phase stability of YSZ particles in MMC is also studied. In addition to that, the residual stress of the MMC is also studied using X-ray diffraction technique (XRD) and efforts are made to correlate the residual stress with the microstructural properties. Based on the mechanical properties and microstructural study, the optimum amount of YSZ in MMC is determined and it is observed that Inconel-1 wt.% YSZ composite coating exhibits better mechanical and metallurgical properties. Furthermore, the effects of process parameters such as laser power, scanning speed, and powder feed rate on the clad geometry, surface roughness, porosity and micro-hardness are also studied. It is observed that the deposition height and width increase with the enhancement of laser power. With the increase of scanning speed, a decreasing trend of deposition height and width is observed.

Presenting Author: Anil Saigal Tufts University

Presenting Author Biography: N/A

Authors:

Gourhari Ghosh Indian Institute of Technology Bombay
Prakhar Jain Indian Institute of Technology Bombay
Anil Saigal Tufts University
Ramesh Singh Indian Institute of Technology Bombay