Estudo da influência da espessura do substrato na dureza de peças fabricadas por manufatura aditiva por deposição a arco (MADA)

Abstract

Additive Manufacturing is among the technologies contemplated by Industry 4.0 and presents itself as a trend in the area of mechanical parts manufacturing. Wire Arc Additive Manufacturing (WAAM) uses the electric arc as a heat source, which gives it a good deposition rate in the manufacture of parts, especially carbon steel. This deposition rate gives the manufactured part an accumulation of heat that directly impacts the cooling rates and consequently the mechanical properties of the manufactured parts. One of the important factors in cooling rates is the thickness of the substrate, which is the base on which the part is built. The objective of this work is to evaluate the influence of substrate thickness on hardness in parts produced by WAAM. For this, three ASTM A36 steel plates with thicknesses of 3.0 mm, 6.35 mm and 12.5 mm were used using the GMAW process. The interaction of temperature, substrate / piece was observed, varying the substrate thickness: The peak temperature reduced as the substrate thickness increased, and for the same substrate the peak temperature values decreased as the layer depositions were being performed. incremented. The cooling rate followed the same behavior, giving higher hardness values for the 12.5 mm thick substrate, right in the first layers, due to the high cooling rates attributed to its thick plate characteristic. As a result of the hardness aspect, Vickers hardness (HV) values were obtained along the cross section of the manufactured part, where it was noticed that the hardness increased due to the increase in substrate thickness. The hardness values were 155.15 HV for the 3.0 mm substrate, 185.10 HV for the 6.3 mm substrate and 187.31 HV for the 12.5 mm thick substrate.