电场作用下316L不锈钢粉末的微成型研究

Study on Micro-forming of 316L Stainless Steel Powder Under Electric Field

采用G1eeble热模拟机,在电场作用下制备了微型316L不锈钢圆柱。根据电场作用下微成型的特点,设计并制造了针对电场烧结微成型的微型模具。采用3种不同工艺,在电场作用下进行了微成型烧结试验。对试样烧结过程进行了描述,对热力学曲线进行了分析。结果表明:在450℃和620℃烧结收缩速率曲线出现明显波动,温度曲线出现明显拐点,分别发生了固相烧结和液相烧结;试样在500℃烧结时,没有发现明显烧结颈,这说明发生了固相烧结;在600℃和800℃烧结时,可观察到烧结颈局部有液相粘接微小区域。

Stainless micro-cylinders were fabricated under electric field by Gleeble thermal instrument. According to the characteristics and properties of micro-fabrication under electric field, a special micro-mould was designed and fabricated. 316L stainless steel powder was sintered under electric field using three different processes. The sintering course was described, and thermodynamic curves were analyzed. The results show that at 450 ℃ and 620 ℃, the contraction rate curve presents obvious fluctuation and the temperature curve presents obvious inflection points, which illustrate that the solid phase sintering and liquid phase sintering happens, respectively. No obvious sintering necks are found when the specimen is sintered at 500 ℃, and solid phase sintering happens. When the specimen is sintered at 600 ℃ and 800 ℃, sintering necks are obviously observed, and micro liquid-banded regions can be observed at local area.