알루미늄 AC4CH 합금주물의 냉각속도 변화에 따른 기계적 물성 예측 및 전산모사 적용

• Published in: 한국주조공학회지 Vol. 38; no. 2; pp. 41 - 47
• Main Authors: 이병준, 조인성, Lee, Byoung-Jun, Cho, In-Sung
• Format: Journal Article
• Language: Korean
• Published: 2018
• Subjects: AC4CH; Computer simulation; Cooling rate; Aluminum casting; Chill; DAS; Porosity
• ISSN: 1598-706X

In a numerical study, equations relating the mechanical properties and cooling rate in a casting process have been applied to an AC4CH cast aluminum alloy. Good agreement was found between the measured and predicted material properties. Step-shaped steel blocks were made to comprise a casting mold with a Y-shaped cavity. Thermometers were inserted into each step of the mold to investigate temperature changes. The microstructure and mechanical properties, such as hardness and tensile stress were measured for each cut of piece. The correlation between the cooling rate and SDAS was found by curved fitting. Moreover, both the solidification time and the temperature were simulated using a commercial package, ZCast. The simulation results for yield strength, tensile strength, elongation, and hardness were compared with experimental results. Using the estimated K and n values, the hardness values of a ship propeller were simulated, and the results were similar to those obtained for actual castings.