反应球磨辅助放电等离子烧结制备超细Al_2O_3颗粒增强Cu基复合材料

Synthesis of ultra fine Al_2O_3 particulates reinforced Cu based composite by reactive milling and spark plasma sintering

采用两步球磨法和放电等离子烧结(SPS)技术制备出超细晶Cu/Al2O3块体复合材料。采用X射线衍射仪,差示扫描量热仪,电子探针,扫描电子显微镜等对复合材料的组织结构进行表征和分析,并对球磨过程中的自蔓延高温合成进行分析。结果表明,Cu和CuO在第一次球磨过程中发生反应获得了混合均匀的Cu/Cu2O复合粉末;第二次球磨使部分的Al固溶到Cu中,且使整个粉末中的Cu2O和Al发生自蔓延高温合成反应,制备出均匀松散的Cu/Al2O3复合粉末。经过SPS烧结得到超细晶Al2O3颗粒增强Cu基复合块体材料,Al2O3颗粒大小为150 nm左右,块体的显微硬度达到220 HV。

Bulk ultra-fine crystalline Cu/A12O3 composites were prepared by two step ball-milling and spark plasma sintering. The microstructure of the samples was characterized and analyzed by means of X-ray diffraction （XRD） , differential scanning calorimeter （DSC）, electron probe microanalysis （EPMA） and scanning electron microscopy （SEM）. The self-propagating high-temperature synthesis （SHS） reaction during the milling process was studied. The results show that a homogeneous Cu/Cu20 powder is obtained by reaction between Cu and CuO during the first milling stage. The second-stage milling makes an amount of A1 diffuse into the Cu matrix. And the SHS occurs in the whole powder leading to the formation of the homogeneous Cu/A12O3 composite powder. The Cu matrix bulk composite reinforced by 150 nm A12O3 particulates is fabrieated by spark plasma sintering. The microhardness of the bulk is 220 HV.