Thermal and electrical conductivity in Al–Si/Cu/Fe/Mg binary and ternary Al alloys

Abstract

This study investigated 30Al-Si, Al-Cu, AlFe, Al-Mg, Al-10Si-Cu, Al-10Si-Fe, and Al-10Si-Mg binary and ternary Al alloys, which are among the most commonly used commercial alloys. The thermal and electrical conductivity of the gravity castings of these alloys were measured. The results indicated that when 1 wt% Si, Cu, or Fe was mixed with commercial Al with 99.8 % purity, the thermal conductivity decreased from 213.5 Wm −1 K −1 to approximately 190-210 Wm −1 K −1 . The thermal conductivity remained at a nearly constant level of 154-157 Wm −1 K −1 when the Si concentration exceeded 6 wt% in the Al-Si alloys. Regarding the Al-Mg alloys, the thermal conductivity did not change when the concentration of Mg was increased to 1 wt%. When the concentration of Mg exceeded 1 wt%, the thermal conductivity decreased greatly from 212.

Microstructures and Mechanical Properties of Al-2Fe-xCo Ternary Alloys with High Thermal Conductivity

“…According to Figure 7, it is worth noting that the conductivity performance of different states for Al-2Fe-xCo alloys are in the following sequence: as-cast < annealing < rolling. It is known that many factors affect the thermal conductivity of alloys, such as alloy composition [2,7,36,37], heat treatment [10,11,38,39], melt treatment [40,41], plastic deformation [1,42], and so on. In our study, compared with the as-cast samples, the thermal conductivities of alloys significantly increase after annealing From Figure 7a, the thermal diffusivity of as-cast specimens first increases from 0.837 cm 2 /s for the Al-2Fe alloy to 0.856 cm 2 /s for Al-2Fe-0.3Co alloy by improving the amplitude of 2.3%, and then gradually decreases with increasing Co content.…”

“…Aluminum alloys possessing higher thermal conductivity always exhibit poor mechanical properties and vice versa. The properties of aluminum alloys are controlled by certain factors, such as the alloying element [ 2 , 7 ], preparation process [ 8 , 9 , 10 ], heat treatment [ 10 , 11 ], etc. Moreover, the specific thermal resistivity (thermal resistivity increment of the alloy derived from unit mass addition) of the alloying elements for Al alloys varies.…”

“…To date, there are few studies that have investigated the relationship between thermal conductivity and Fe content in Al alloys. Chen et al [ 7 ] showed that adding an appropriate amount of Fe element slightly improved the thermal conductivity of an Al-10Si alloy. Our research team pointed out that this improvement was attributed to the coupling effect between Fe and Si.…”

“…Our research team pointed out that this improvement was attributed to the coupling effect between Fe and Si. However, the Si element significantly decreases the thermal conductivity of aluminum alloys [ 7 , 15 ]. For example, when the Si concentration reached 4 wt.%, the thermal conductivity of the Al-Si alloys dropped from 213.5 W/(m·K) to 165.1 W/(m·K) [ 7 ].…”

A Study of the Mechanical and Thermal Characteristics of an Al-Si-Fe Alloy Fabricated by Rolling and Heat Treatment

“…Although solid solubility has a great influence on the thermal conductivity of alloys, Lumley et al [7] treated die cast alloys by using a T7 temper and reported that the thermal diffusivity and thermal conductivity of the alloy increased. Chen et al [8] suggested that precipitation and heat treatment could influence the thermal conductivity of aluminum alloys by experimentally and computationally investigating binary and ternary Al alloys. Thus, many researchers have attempted to enhance the thermal properties of aluminum alloys by various heat treatments.…”