Gazi Üniversitesi Fen Bilimleri Dergisi (Jun 2019)
Investigation of the Wear and Machinability Properties of Laser Coated AA7075 Aluminum Alloy Materials
Abstract
In this study, ZrB2 nanoparticles which is synthesized by the mechanochemical method were coated on the surface of AA7075 aluminum alloy with CO2 laser. Two different experimental sets were performed to determine the effect of laser power and laser scanning speed on coating layers. At the first experimental set, the scanning speed of 1000 mm / min was kept constant, and experiments were performed at 50, 70 and 100W laser powers, in the other experiment set, 70W laser power was kept constant and experiments were performed at 300, 500 mm / min scanning speed. Phase structures and morphological properties of the coating layer were investigated by X-Ray diffractometer, scanning electron microscopy, and optical microscope. The wear resistance and hardness of the coating layers were determined by ball-on-disc wear device and microhardness device. To determine the machinability properties, the coated samples are then cut with abrasive water jet, wire erosion, laser and abrasive disc, respectively, and characterized. It was determined that the hardness of substrate increased from 110 HV to 190 HV after coating processes. In spite of the minimal heat input compared to other methods, although the abrasive water jet was prominent, the least damage was observed in the cutting with abrasive disc. It has been determined that the most suitable cutting method is the abrasive disc cutting method for laser coated samples.
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