【摘要】 利用放电等离子烧结装置考察了纳米铜粉坯体的升温过程,研究了烧结速度和烧结温度对烧结等效电阻、烧结体相对密度及晶粒尺寸的影响。结果表明:在烧结过程中存在着最佳的烧结速度,当烧结速度为15 0℃ min时,样品致密度达到峰值88%左右,晶粒的平均尺寸接近2 0 0nm ,且烧结的等效电阻随升温速度的增加而降低;纳米Cu粉末在2 5 0℃时开始烧结成块,随烧结温度提高,烧结致密度不断提高,电阻降低;但是当升温速度过快,烧结温度过高时,出现反致密化现象。更多还原

【Abstract】 The sintering process of compacts of nanocrystalline Cu powder by spark plasma sintering (SPS) was investigated with emphasis on the effects of the temperature and sintering rate on grain size, relative density and electrical resistances of the samples by SPS. The results show that the sintered sample of nanocrystalline Cu powders with a relative density of 88% and average grain size of 200nm can be obtained by SPS at heating rate of 150℃/min.The electrical resistance of the sintered samples decreases with increasing the sintering rate and temperature. The nanopowders of Cu can not bind when the temperature is below 250℃, and beyond that the higher the sintering temperature, the higher relative density of sample can be obtained. However,it is also found that the density of samples reduces if the sintering temperature excesses 450℃, or heating rate excesses 150℃/min.更多还原