EFFECT OF SCRAP RATIO ON LIQUID METAL QUALITY OF LOW-PRESSURE DIE-CASTING (LPDC) ALLOY USING ROTARY DEGASSING

Although various processes are used in aluminum liquid metal cleaning, environmentally friendly, economical and applicable methods should be preferred in industry. Among these methods, the Density Index test based on the reduced pressure test (RPT), which is widely used to measure the efficiency of the rotary degassing process, and the K-mold test method, which offers fast and practical results were carried out. The effects of rotary degassing method on the liquid metal quality of AlSi7Mg0.3 (A356) aluminum alloy charges prepared with different proportions of scrap and ingots were evaluated using a constant 5l/min gas flow rate, a constant 5 min process time and a constant 300 rpm rotor rotation speed. The results show that the Density Index values can be reduced from 1.48% to around 0.74% with increasing scrap rate, while K-mold values can be reduced from 2.8 to 0.6. It was also shown that the rotary degassing method is effective in liquid metal cleaning, and the K-mold test can be used as a very practical control tool for evaluating liquid metal quality.