Session: 03-10-02: Laser-Based Advanced Manufacturing and Materials Processing

Paper Number: 146302

146302 - Substract Surface Quality Influence on Lp-Ded Parameterization: Exploring Effects on Bead Characteristics and Microstructure 

LP-DED laser powder is continually permeating the boundaries of traditional manufacturing through technological innovations in which Industry 4.0 has shown itself to be a leading force. Its versatility in handling materials, such as heat, light and cold, can also be noted as well as its capacity to make intricate patterns, and rehabilitation of broken parts. Specifically, due to the intrinsic process, a starting substrate is to be the base for the deposition to happen onto, and depending on the used base material and the added powder used, different intermetallic reactions and behaviors are observed. Specific findings regarding the low-power density and emission from direct-ED ultraviolet are discussed in a wide range of essential LP-DED literature. The production of the LP-DED process oversees several parameters, which are power, mass flow, and feed rates. The production quality depends on the overall bead characteristics such as height, width, porosity, and dilution significantly. These parameters not only determine factors that more or less directly influence the behavior of finished parts, they also determine the quality of mechanical and microstructural properties produced thus the process of parameterization becomes meticulous and thorough. This study will analyse the extent to which the surface quality of the substrate (roughness, its heat absorption) will affect such factors as the size of beads and their microstructure, and the layer growth in LP-DED machines through experiments carried out on both commercial and laboratory grade AISI H-13 powder. This parameter is met in this study by applying an analytical model to figure out the initial deposition of the object on different surfaces and then cubes are deposited. The experimental bosy looked at the initial growth properties of the first despited layer on the various surfaces. Microstructural and porosity examination was carried out with Scanning Electron Microscopy (SEM), by sampling the cross-section of the beads. While surface topography parameters were gained for the top layer surface. Furthermore, it was determined the hardness characteristics via nano hardness measurement. The observations obtained indicate that a high criterion of the quality of the surface will do noticeable damage to the parameterization which in turn, will not allow the optimum work of the process. It was found out that the opaque piece had 20% dilution more than the mirror-finished surface, and the latter had a little bit more increase (15%) in the first layer growth than the opaque piece. Moreover, this behavior of the mixtures on opaque surfaces has proven to have better stability. Similarly, in terms of powders, we discovered that energy intensity for the laboratory-produced powder was higher than the powder obtained using a more environmentally friendly method probably because of the defects present in the manufacturing process. To sum up, the LP-DED process takes up substrate surface as a basis for the parameterization, which may in certain cases even require a 10% increase in the powder consumption, a 10% decrease in power consumption, but also has a major influence on mechanical properties of the resulting components.

Presenting Author: Johan Grass Nuñez University of São Paulo

Presenting Author Biography: Aeronautical engineer with a master's degree in mechanical engineering from the University of São Paulo. Currently, in PhD position in Mechanical Engineering at the University of São Paulo.

Authors:

Johan Grass Nuñez University of São Paulo
Juan Pereira University of São Paulo
Alessandro Rodrigues University of São Paulo
Reginaldo Texeira University of São Paulo