改进爆炸实验装置,并利用该装置实施了预热爆炸压实实验。以商业ITO纳米陶瓷粉末为原料,通过压力机将粉末压实到大约50%理论密度的初始压坯,选择预热温度为800℃以上进行爆炸压实,从而获得了致密且晶粒在纳米量级的良好烧结体。结果表明:预热爆炸烧结体微观组织结构均匀,晶粒尺寸分布在200nm左右,且将烧结体在扫描电镜上放大到100,000倍时仍未发现明显孔洞和微裂纹等缺陷。认为宏观塑性变形和晶粒长大是导致良好烧结的2个主要机制。
Pre-heat explosive consolidation experiments have been performed by using an improved explosive experiment equipment. Commercial ITO nanopowders were compacted to about 50% of the theoretical density by a punch, then to be consolidated by explosion at pre-heat temperature of above 800 ℃. The dense and high quality sintering bulks have been produced with grain size of about 200 nm and uniform microstructures and observed by SEM at 100 000 multiples without pores and micro-cracks on the cross-section of sample. The mechanism of nanopowders by the pre-heat explosive consolidation process is roughly discussed and considered that the plastic deformation in macro-scale and the grain coarsening are the two main mechanisms for good sintering