掺杂Fe基非晶合金调控Ni-金刚石/Al复合材料的导热性能

Control of thermal conductivity of Ni-Diamond/Al composite by doping Fe-based amorphous alloy

通过对金刚石表面化学镀Ni对金刚石颗粒镀覆金属层进行表面改性。采用X射线衍射仪(XRD)对Fe基非晶合金进行物相分析,利用差示扫描量热仪(DSC)测试Fe基非晶粉的特征温度点,采用扫描电子显微镜(SEM)观察界面结合情况和界面产物微观形貌,用能谱仪(EDS)进行物质元素分析,采用激光热导仪(LFA 447)对复合材料进行热扩散系数测试。结果表明:充分利用Fe基非晶合金相转变过程中的原位自放热,提升Al液的流动性,增强了金刚石/Al复合材料的界面结合能力。Fe基非晶合金相转变后多组元晶体的形核和长大,提高了复合材料界面热阻,降低了金刚石/Al复合材料的峰值导热性能。Fe基非晶的引入提高了金刚石/Al复合材料的导热稳定性,在测试温度范围内,导热稳定性提高10.3%。引入过量的Fe基非晶合金或过长的制备时间会引起金刚石颗粒发生碳化。

The surface of diamond was modified by electroless plating Ni on the surface of diamond particles.X-ray diffraction(XRD)was used to analyze the phase of Fe-based amorphous alloy.The characteristic temperature point of Fe-based amorphous powder was measured by DSC.Scanning electron microscoper(SEM)was used to observe the interface bonding and the micro morphology of the interface products.The material elements were analyzed by EDS.The thermal diffusivity of the composite was measured by laser thermal conductivity analyzer(LFA 447).The results show that,the in-situ self-exothermic heat during the crystal transformation of Fe based amorphous alloy is fully utilized to improve the fluidity of Al liquid and enhance the interface bonding of diamond/Al composite.After crystallization,the nucleation and growth of multi-component crystals of Fe based amorphous alloy increase the interfacial thermal resistance of the composite and reduce the thermal conductivity of diamond/Al composite.The introduction of Fe-based amorphous alloy improves the thermal stability of diamond/Al composite,which increases by 10.3%in the test temperature range.Too much Fe-based amorphous alloy or too long preparation time will lead to carbonization of diamond particles.