Influence of Deep Etching Surface Treatment to The Tensile Strength and Microstructure of Brazing Aluminium - Mild Steel

Abstract

Since hard metals are among the materials that liquid brazing alloys scarcely adhere to, they should not be brazed without first removing the surface layer after sintering. The electrolytic etching method, which gives the surfaces of materials that are hardly wettable very good energetic qualities, is given specific attention. Deep etching is done by using a high concentration of acid solution to roughen the surface. Both dry and wet settings are suitable for etching. An etching fluid is used for etching in a wet environment. Typically, the plate or metal is submerged in an etching solution, where the substance is chemically broken down. While in dry etching, the plasma’s gas phase is where the etching takes place. Due to the presence of plasma in this situation, the etching process that takes place combines chemical and physical processes. Plasma etching is another name for dry etching. Deep etching is an etching process to obtain a rougher surface. Wet deep etching requires a longer immersion time and even several immersions are required. The purpose of this study was to determine the effect of etching treatment in the brazing process of Aluminium-Mild steel for its microstructure and mechanical properties. The specimens in this study used aluminium 6000 series, mild steel, Alusol ER4043, and etching fluid. Mild steel surfaces are deep etched before brazing. Specimen manufacturing standard refers to ASTM D1002. A micro photo test was conducted to compare the surface conditions of aluminium and mild steel with and without etching treatment. The deep etching process is carried out in three variations of time, namely 20, 30, and 40 minutes. The results showed that the tensile strength increased with deep etching treatment on the surface.