Experimental Study on the Relationship between Cooling Rate, Secondary Dendrite Arm Spacing and Tensile Properties in Aluminum Casting

Abstract:

The dendritic microstructure formed during solidification plays a critical role in determining the mechanical properties of aluminum castings. In particular, secondary dendrite arm spacing (SDAS) is strongly influenced by the cooling rate and is closely related to yield strength, ultimate tensile strength, and elongation. However, experimental validation of these relationships requires a consistent methodology for defining cooling rate and linking it to microstructural and mechanical measurements. In this study, an experimental framework was established to investigate the relationships among cooling rate, SDAS, and mechanical properties in aluminum castings. Casting blocks with different thicknesses were fabricated to obtain a wide range of cooling rates. Cooling curves were measured during solidification, and cooling rates were determined using the second derivatives of the cooling curves. SDAS measurements and tensile tests were conducted on specimens extracted from symmetric positions within the casting blocks to ensure equivalent thermal histories. The results showed that the cooling rate–SDAS relationship exhibited a linear trend on a logarithmic scale, consistent with previously reported correlations. Smaller SDAS values were associated with increased yield strength, ultimate tensile strength, and elongation. The agreement between the present results and literature data confirms the validity of the proposed experimental framework for correlating solidification conditions, microstructure, and mechanical properties of aluminum castings.

• Periodical: Solid State Phenomena (Volume 390)
• Pages: 111-119
• DOI: https://doi.org/10.4028/p-os8U1C
• Online since: April 2026
• Authors: Taegyun Ahn*, Juwon Lee, Janghoon Lee, Jeong Whan Yoon
• Keywords: Aluminum Casting, Cooling Rate, Mechanical Properties, Secondary Dendrite Arm Spacing (SDAS), Thermal Analysis

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