The utralow-temperature superplastic forging for sialon-based nanocomposites is reported for the first time. Sialon-based nanocomposites, with an average grain size smaller than 50 nm and 98.5% relative density, were prepared with nano-sized row powders by the spark plasma sintering (SPS) technique at a record ultralow sintering temperature of 1150 °C. An excellent gear is forged at the ultralow deformation temperature of 1200 °C with nanosized grains without any cracking. The maximum strain rate achieved is over 10−1 s−1, and a compression strain is more than 0.9. The practical application for superplastic forming of nitrogen ceramics is much more difficult than that for oxide ceramics because of the high deformation temperature and low strain rates. The present findings present a bright prospect for the near-net-shape superplastic forming of nitrogen ceramics.
展开▼
机译：首次报道了基于赛隆的纳米复合材料的超低温超塑性锻造。通过火花等离子体烧结（SPS）技术，以纳米级的行粉末，在创纪录的1150 C的超低烧结温度下，制备了平均粒径小于50 nm，相对密度为98.5％的Sialon基纳米复合材料。出色的齿轮是在1200 C的超低变形温度下锻造而成的，具有纳米级晶粒而没有任何裂纹。达到的最大应变率超过10 -1 s -1 ，压缩应变大于0.9。由于高变形温度和低应变速率，氮氧化物陶瓷超塑性成形的实际应用要比氧化物陶瓷困难得多。目前的发现为氮陶瓷的近净形超塑性成形提供了光明的前景。
展开▼
