• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2023, Vol. 59 ›› Issue (17): 250-257.doi: 10.3901/JME.2023.17.250

• 数字化设计与制造 • 上一篇    下一篇

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选区激光熔化NiTi形状记忆合金成形与热处理

黄祥辉1, 曹睿博2, 郑睿恒2, 马飞豪2, 蒋益雪2, 詹章瑜2, 于天宇3, 康楠1   

  1. 1. 巴黎高科国立工程技术学院 香槟沙隆 13067 法国;
    2. 西北工业大学材料学院 西安 710072;
    3. 哈尔滨工业大学机器人技术与系统国家重点实验室 哈尔滨 150001
  • 收稿日期:2022-09-20 修回日期:2023-03-11 出版日期:2023-09-05 发布日期:2023-11-16
  • 通讯作者: 康楠(通信作者),男,1988年出生,博士,副教授,博士研究生导师。主要研究方向为金属增材制造过程中的成形控制与成型机理。E-mail:nan.kang@ensam.eu
  • 作者简介:黄祥辉,男,1995年出生,博士研究生。主要研究方向为NiTi形状记忆合金的增材制造。E-mail:xianghui.huang@ensam.eu;曹睿博,男,2000年出生,本科生。主要研究方向NiTi形状记忆合金的增材制造。E-mail:caoruibo@mail.nwpu.edu.cn
  • 基金资助:
    国家留学基金委基金(202106230079)和机器人技术与系统国家重点实验室开放研究(SKLRS-2022-KF-10)资助项目。

Fabrication and Heat Treatment of Selective Laser Melting Produced NiTi Shape Memory Alloy

HUANG Xianghui1, CAO Ruibo2, ZHENG Ruiheng2, MA Feihao2, JIANG Yixue2, ZHAN Zhangyu2, YU Tianyu3, KANG Nan1   

  1. 1. Arts et Metiers ParisTech. Chalon en Champagne 13067, France;
    2. School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072;
    3. State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001
  • Received:2022-09-20 Revised:2023-03-11 Online:2023-09-05 Published:2023-11-16

摘要: 增材制造以灵活的结构设计与制造手段为NiTi形状记忆合金提供了更多可能的应用,然而激光增材成形制造完全致密的NiTi复杂结构构件仍存在挑战。研究激光扫描速度对Ni50.9Ti49.1(at%)粉末成型试样致密度和组织形貌的影响规律具有重要意义。所选的400~1 400 mm/s工艺窗口内,试样致密度均大于99%。但当扫描速度大于600 mm/s时底部会产生裂纹。优选打印速度400 mm/s的拉伸实验结果表明:沉积态试样和热处理试样平均抗拉强度分别为675 MPa和782 MPa,最大延伸率分别为19.7%和和17.95%,即500℃退火热处理后试样抗拉强度提升,但延伸率下降。沉积态和热处理态试样断裂机制为脆性与塑性断裂共同作用的准解理断裂机制。通过DSC实验测得热处理后试样的马氏体相变和逆相变起始温度MsAs分别为35.8℃、10.0℃。温度介于二者之间时,合金由奥氏体、马氏体两相组成,EBSD结果表明20℃室温下试样主要由B19'马氏体构成。

关键词: 选区激光熔化, NiTi形状记忆合金, 扫描速度, 致密度, 抗拉强度

Abstract: Although additive manufacturing provides more possibilities for NiTi shape memory alloy with flexible structural design, there are still challenges in fabricating fully dense NiTi components with complex structure by laser additive manufacturing. Studying the influence of laser scanning speed on the density and surface quality is very significant. In the selected process window of 400~1 400 mm/s, the relative density of samples was greater than 99%. But when the scanning speed was greater than 600 mm/s, cracks appeared at the bottom. The results of tensile tests at an optimized printing speed of 400 mm/s show that the average tensile strength of the deposited and heat treated specimens were 675 MPa and 782 MPa, respectively. And the maximum elongation of deposited specimens and heat treated specimens were 19.7% and 17.95% respectively. That means, the tensile strength of the specimen increases after the 500℃ annealing heat treatment, but the elongation decreases. The fracture mechanism of the deposited and heat treated specimens is the joint action of cleavage and plastic fracture. The martensitic phase transformation and inverse phase transformation starting temperatures (Ms and As) for the heat-treated specimens were 35.8℃ and 10.0℃, respectively, which is obtained by DSC experiments. For temperature between Ms and As, the alloy consists of austenite and martensite phases. The EBSD results revealed that the specimens were mainly composed of B19' martensite at 20℃ room temperature

Key words: selective laser melting, niti shape memory alloy, scanning speed, relative density, tensile strength

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