金刚石/硅复合材料的制备和导热性能

为探索新型热沉用散热材料,采用高温高压方法烧结制备了金刚石/硅复合材料,并研究了金刚石大小粒度混粉、金刚石含量、渗硅工艺以及金刚石表面镀钛对复合材料的致密度和导热性能的影响.结果表明:在大粒度金刚石粉中掺入小粒度金刚石粉、渗硅和金刚石表面镀钛处理都可提高金刚石/硅复合材料的致密度和热导率;随着金刚石含量增大,复合材料热导率提高;其中75/63μm镀钛金刚石颗粒与40/7μm金刚石颗粒的混粉,当混粉质量分数为95%时,在4～5GPa、1400℃高温高压渗硅烧结,金刚石/硅复合材料的热导率可高达468.3W·m^-1·K^-1.

Preparation and thermal conductivity of diamond/Si composites

In order to develop a new heat-spreading material used as heat sink,diamond/Si composites were synthesized by a high-pressure high-temperature(HPHT) method.An investigation was conducted on the effects of diamond particle size,diamond content,siliconizing process,and coating Ti on diamond particles on the density and thermal conductivity of the composites.The results show that mixing large and small size diamond particles,coating Ti and siliconizing process are effective to improve the density and thermal conductivity of diamond/Si composites.The thermal conductivity rises with the content of diamond increasing.When the mass fraction of diamond blended by 75/63μm Ti-coated diamond particles and 40/7μm diamond particles is 95%,the thermal conductivity of the composite sintered at 4~5GPa and 1400℃ by the HPHT siliconizing method can reach to 468.3W·m^-1·K^-1.