Evaluation of the Effect of Nd Content and Extrusion Process on Thermal Conductivity of Mg-Mn-Zn-Nd Alloys

Ying-Long Zhou,Jie Liu,Dong-Mei Luo,Dong-Chu Chen

doi:10.3390/cryst8110427

Abstract

The thermal conductivity of the Mg-1Mn-2Zn-xNd alloys (x = 0.5, 1.0, 1.5 wt. %) was studied for the potential applications of heat dissipation. The phase constituents were examined by X-ray diffraction analysis, and the microstructure was observed by light and scanning electron microscopes. The thermal conductivity of the Mg alloys was gauged at room temperature using laser flash method. The experimental results indicate that the thermal conductivity of both the cast and extruded Mg alloys decreases slowly with Nd content, and the extrusion process remarkably reduces the grain sizes and thermal conductivity of the Mg alloys. The thermal conductivity of cast Mg-1Mn-2Zn-xNd alloys exceeds the required critical value (100 W/(m·k)) for the cast Mg alloys. Among them, the cast Mg-1Mn-2Zn-1Nd alloy has great potential to be a good candidate of heat dissipation materials due to its good combination of thermal and mechanical properties.

Highlights

The rapid development of various electronic devices demands higher heat dissipation performance of metal fins
Nd content, which is much lower both the cast and extruded Mg alloys slowly decreases with addition of Nd content, which is much than of pure
It can be observed that the thermal conductivity of both the cast and extruded Mg alloys slowly decreases with addition of Nd content, which is much lower thermal conductivity than that of pure Mg (156 W/(m·K))

Summary

Introduction

The rapid development of various electronic devices demands higher heat dissipation performance of metal fins. Silver and gold are precious metals with very high price, and copper has its own disadvantages: high cost, large weight and poor corrosion resistance. This is the reason why the light Al alloys are often used to manufacture the most currently-used heat sinks. Mg has good thermal conductivity of 156 W/(m·K) at room temperature, which is only lower than that of pure Al among the commercially-used metallic materials [1], and it has much lower density (about 1.8 g/cm3 ) and higher specific heat capacity as compared with the above metals.

Results

Discussion

Conclusion