Effect of dendritic arm spacing on mechanical properties and corrosion resistance of Al 9 Wt Pct Si and Zn 27 Wt Pct Al alloys

Abstract

It has been reported that the mechanical properties and the corrosion resistance (CR) of metallic alloys depend strongly on the solidification microstructural arrangement. The correlation of corrosion behavior and mechanical properties with microstructure parameters can be very useful for planning solidification conditions in order to achieve a desired level of final properties. The aim of the present work is to investigate the influence of heat-transfer solidification variables on the microstructural array of both Al 9 wt pct Si and Zn 27 wt pct Al alloy castings and to develop correlations between the as-cast dendritic microstructure, CR, and tensile mechanical properties. Experimental results include transient metal/ mold heat-transfer coefficient (h i), secondary dendrite arm spacing (l 2), corrosion potential (E Corr), corrosion rate (i Corr), polarization resistance (R 1), capacitances values (Z CPE), ultimate tensile strength (UTS, s U), yield strength (YS, s y), and elongation. It is shown that s U decreases with increasing l 2 while the CR increases with increasing l 2 , for both alloys experimentally examined. A combined plot of CR and s U as a function of l 2 is proposed as a way to determine an optimum range of secondary dendrite arm spacing that provides good balance between both properties.

Characterization of Three-Dimensional Dendritic Structures in Nickel-Base Single Crystals for Investigation of Defect Formation

“…The predominant measures are the primary and secondary dendrite arm spacings (PDAS and SDAS respectively) [24][25][26][27][28][29][30][31][32]. It has been well documented that fundamental relationships exist between dendrite arm spacing and casting parameters of growth rate (V) and thermal gradient (G).…”

An Experimental Study of the Solidification Thermal Parameters Influence upon Microstructure and Mechanical Properties of Al-Si-Cu Alloys

“…Currently a large part of the concepts and methods developed in support of solidification research, which is the main phenomenon that occurs during casting, can be applied on an industrial scale, allowing a visible improvement in the manufactured parts quality, making solidification studies a powerful tool for its economic potential 3 . The microstructure effects on metallic alloys properties has been highlighted in various studies and particularly, the grain size influence and dendrite arm spacing upon the mechanical properties has been reported 1,4 . There are a lack of studies about multicomponent alloys solidification in transitional arrangements on specific literature 5 .…”

Emergence and Progression of Abnormal Grain Growth in Minimally Strained Nickel-200

“…AGG is of significance because, like many other grain-scale and sub-grain-scale features such as freckles [1,2], precipitates [2], or dendrite arm spacing [3], AGG has been shown to have a significant effect on properties across many material systems under various loading conditions [4][5][6][7]. The exact mechanisms underpinning the occurrence of AGG are still unclear and remain a subject of much interest and research.…”