Effect of fabrication method on the structure and properties of a nanostructured nickel-free stainless steel
Effect of fabrication method on the structure and properties of a nanostructured nickel-free stainless steel
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DOI：
10.1016/j.apt.2020.06.025
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发表时间：
2020-08-01
影响因子：
5.2
通讯作者：
Tayebi, L.
中科院分区：
文献类型：
--
作者：
Heidari, L.;Tangestani, A.;Tayebi, L.
采用两种不同的粉末冶金方法--热粉末锻造(HPF)和粘结剂辅助挤压(BAE)方法制备了ASTM F2581纳米结构不锈钢。对它们的结构和力学性能进行了研究和比较。在这两种制备方法中，合金粉末都是使用主要合金元素通过机械合金化并添加烧结助剂来制备的。在BAE法中，合金粉末与聚合物混合，然后冷挤压、聚合物去除和烧结得到糊料。在HPF法中，合金粉末是在高压下热锻造的。用扫描电子显微镜(SEM)、有限元扫描电子显微镜(FE-SEM)、X射线衍射仪(X射线衍射仪)和透射电子显微镜(TEM)对样品的奥氏体晶相结构和尺寸进行了分析。结果表明，HPF法制备的样品通常比BAE法制备的样品密度高。在HPF法中，孔洞较小，大小和形貌几乎都是均匀的。此外，还对样品进行了显微硬度和拉伸测试。结果表明，BAE试件的延性高于HPF试件。BAE样品的断口有较深的韧窝，表明BAE样品具有较高的延性。另一方面，HPF试样的硬度和强度均高于BaE试样。结果表明，两种方法得到的试件均比常规316L不锈钢具有更高的强度和硬度。(C)2020年日本粉末技术学会。由Elsevier B.V.和日本粉末技术学会出版。版权所有。
An ASTM F2581 nanostructured stainless steel was fabricated by two different powder metallurgy routes; Hot Powder Forging (HPF) and Binder Assisted Extrusion (BAE) methods. Their structure and mechanical properties were investigated and compared. In both fabrication methods, the alloy powder was made by using main alloying elements through mechanical alloying, along with the addition of a sintering aid. In the BAE method, a paste was prepared by mixing alloy powders with polymer followed by cold extrusion, polymer removal, and sintering. In the HPF method, the alloy powders were hot forged under high pressure. The structure and the size of the austenite crystallite of the samples were investigated by scanning electron microscopy (SEM), FE-SEM, x-ray diffraction (XRD) and transmission electron microscopy (TEM). It was determined that the samples prepared by the HPF method are generally denser than those made via BAE. The porosities are smaller and almost uniform in size and morphology in the HPF method. Furthermore, microhardness and tensile tests were performed on the samples. The results show that the ductility of BAE samples is higher than the HPF samples. The fracture surface of the BAE sample has deeper dimples, indicating higher ductility for BAE samples. On the other hand, both the hardness and strength of HPF samples are higher than those of the BAE samples. The results show that both methods produced specimens with considerably higher strength and hardness than conventional 316L stainless steel. (c) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.