Properties of as-deposited and heat-treated Ni-Mn-Ga magnetic shape memory alloy processed by directed energy deposition
Properties of as-deposited and heat-treated Ni-Mn-Ga magnetic shape memory alloy processed by directed energy deposition
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DOI：
10.1016/j.jallcom.2018.04.059
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发表时间：
2018-07-05
影响因子：
6.2
通讯作者：
Chmielus, Markus
中科院分区：
文献类型：
--
作者：
Toman, Jakub;Mullner, Peter;Chmielus, Markus
采用激光金属沉积增材制造方法制备了Ni-Mn-Ga磁性形状记忆合金。用于沉积的粉末是从铸造的10M马氏体Ni-Mn-Ga锭中粉碎出来的。沉积的样品具有铁磁性，呈现14M马氏体，除了衬底和镀层之间有一层薄层外，没有检测到宏观成分的差异。由于局部热历史的差异，逐层沉积导致层状微观结构，并且样品的宽转变温度范围被认为源于由此产生的微观结构变化。虽然样品是明显的多晶，但柱状晶粒跨越沉积层，这可能有利于孪晶界运动。经过均匀化和有序热处理后，相变恢复了典型的窄磁滞，饱和磁化强度增加，晶粒生长和/或再结晶发生。结果表明，基于激光的增材制造工艺有望生产磁性形状记忆合金。(C) 2018 Elsevier B.V.版权所有
Ni-Mn-Ga magnetic shape memory alloy was processed by laser metal deposition, an additive manufacturing method. Powder used for deposition was crushed from a cast 10M martensite Ni-Mn-Ga ingot. The deposited sample was ferromagnetic and showed a 14M martensite with no detected macroscopic composition differences throughout, except for a thin layer between substrate and deposit. Layer-by-layer deposition resulted in a layered microstructure due to differences in local thermal histories, and the sample's broad transformation temperature range is proposed to originate from the resulting variations in microstructure. Although the sample is clearly polycrystalline, columnar grains span deposition layers, which is potentially favorable to twin boundary motion. After a homogenizing and ordering heat treatment, transformations regained a typical narrow hysteresis and saturation magnetization increased, while grain growth and/or recrystallization took place. The results show the promise of laser-based additive manufacturing processes for production of magnetic shape memory alloys. (C) 2018 Elsevier B.V. All rights reserved.