Microstructure and transformation of Al-containing nanostructured 316L stainless steel coatings processed using spark plasma sintering
Microstructure and transformation of Al-containing nanostructured 316L stainless steel coatings processed using spark plasma sintering
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DOI：
10.1016/j.jmatprotec.2010.07.023
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发表时间：
2010-11
影响因子：
6.3
通讯作者：
A. Almathami;M. Brochu
中科院分区：
文献类型：
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作者：
A. Almathami;M. Brochu
采用低温球磨和放电等离子烧结技术制备了Al含量分别为0%、2%和6wt%的奥氏体不锈钢合金。结果表明，铝对球磨过程中的应变诱导相变有影响。球磨后的粉末由细小分散的颗粒组成，其粒度分布随铝浓度的增加而增大。通过放电等离子烧结(SPS)工艺将SS0Al(含0wt.%Al的不锈钢)粉末固结到固体不锈钢衬底上，由于低温球磨产生的原始颗粒形态，产生了等轴结构。由于颗粒的长径比增大，SS2Al和SS6Al SPS固结粉末涂层呈现出层状结构。三种粉末体系在低温球磨过程中诱导的体心立方结构向面心立方转变的程度与Al含量有关。与传统的粉末固结热处理相比，SPS工艺对催化裂化回收率的影响最小。SPS过程提供的能量不足以克服控制位错重排的激活能，这是完成FCC恢复所需的。通过控制涂层中bcc/fcc晶体的比例，发现SPS处理涂层的显微硬度高度依赖于Al含量。
Three austenitic stainless steel alloys containing 0, 2 and 6wt.% Al were prepared by cryomilling and spark plasma sintering. It was shown that aluminum influences the strain-induced phase transformation that occurs during milling. The milled powders consisted of finely dispersed particles with the powder particle size distribution increasing with aluminum concentration. Consolidation of the SS0Al (stainless steel containing 0wt.% Al) powder via the spark plasma sintering (SPS) process onto a solid stainless steel substrate yields an equiaxed structure due to the original particle morphology resulting from cryomilling. The SS2Al and SS6Al SPS consolidated powder coatings exhibit a lamellar structure due to the increased aspect ratio of the particles. The degree to which the BCC structure induced during cryomilling of all three powder systems reverted to FCC was dependent upon the Al content. The SPS process was found to minimally influence the FCC recovery compared to conventional powder consolidation heat treatments. The energy supplied by the SPS process was insufficient to overcome the activation energy governing the rearrangement of dislocations required to complete the FCC recovery. The microhardness of the coatings processing using SPS was found to be highly dependent on the Al content by controlling the ratio of the BCC/FCC crystals in the formed coating.