Abstract:
Thermal transport is of grave importance in many high-value applications. Heat dissipation can be improved by utilizing liquid metals as thermal interface materials. Yet, liquid metals exhibit corrosivity towards many metals used for heat sinks, such as aluminum, and other electrical devices (i.e., copper). The compatibility of the liquid metal with the heat sink or device material as well as its long-term stability are important performance variables for thermal management systems. Herein, the compatibility of the liquid metal Galinstan, a eutectic alloy of gallium, indium, and tin, with diamond coatings and the stability of the liquid metal in this environment are scrutinized. The liquid metal did not penetrate the diamond coating nor corrode it. However, the liquid metal solidified with the progression of time, starting from the second year. After 4 years of aging, the liquid metal on all samples solidified, which cannot be explained by the dissolution of aluminum from the titanium alloy. In contrast, the solidification arose from oxidation by oxygen, followed by hydrolysis to GaOOH due to the humidity in the air. The hydrolysis led to dealloying, where In and Sn remained an alloy while Ga separated as GaOOH. This hydrolysis has implications for many devices based on gallium alloys and should be considered during the design phase of liquid metal-enabled products.
摘要:
热传输在许多高价值应用中是非常重要的。可以通过利用液态金属作为热界面材料来改善散热。然而,液态金属对许多用于散热器的金属表现出腐蚀性,如铝,和其他电气设备(即,铜)。液态金属与散热器或器件材料的相容性及其长期稳定性是热管理系统的重要性能变量。在这里,液态金属Galinstan的相容性,镓的共晶合金,铟,还有锡,仔细研究了金刚石涂层和液态金属在这种环境中的稳定性。液态金属不渗透金刚石涂层也不腐蚀它。然而,液态金属随着时间的推移而凝固,从第二年开始。经过4年的老化,所有样品上的液态金属凝固了,这不能用钛合金中铝的溶解来解释。相比之下,凝固是由氧气氧化引起的,然后由于空气中的湿度水解为GaOOH。水解导致脱合金,其中In和Sn保持合金,而Ga分离为GaOOH。这种水解对许多基于镓合金的设备都有影响,应该在液态金属使能产品的设计阶段加以考虑。