Selective laser melting of maraging steel: mechanical properties development and its application in mold
Selective laser melting of maraging steel: mechanical properties development and its application in mold
复制标题
DOI：
10.1108/rpj-05-2017-0104
复制
发表时间：
2018-01-01
影响因子：
3.9
通讯作者：
Wang, Di
中科院分区：
文献类型：
--
作者：
Bai, Yuchao;Yang, Yongqiang;Wang, Di
目的：验证选择性激光熔凝(SLM)能否用于制造具有保形冷却通道的模具，并确定SLM制造马氏体时效钢模具的力学性能发展是否有利于提高模具质量。设计/方法/途径-用SLM制造一系列块状试件和柱状拉伸试件，然后分别进行固溶处理(ST)和固溶+时效处理(ST+AT)。研究了试件的显微组织、显微硬度和抗拉强度的变化。然后，用SLM设计制造了一种带有保形冷却通道的模具，并对模具进行了ST加工，显微硬度下降。发现不同热处理下的组织形态差异很大。模具经ST处理后，显微硬度和抗拉强度下降，胞状组织断裂，有利于模具的机械光整加工，提高表面精度。之后，随着Ni3Mo、Fe2Mo和Ni3Ti颗粒的析出，AT显著提高了结晶器的硬度和强度。用SLM成功地制造出具有共形冷却通道的马氏体时效钢模。与传统的具有简单冷却通道的模具相比，采用SLM可以直接加工出具有保形冷却通道的模具。SLM直接制造马氏体时效钢模具可以降低硬度，有利于机械光整，克服了SLM直接制造模具精度低的缺点。这为制造高质量的模具提供了一条新途径。
Purpose - This paper aims to verify whether selective laser melting (SLM) could be used for manufacturing mold with conformal cooling channels and determine whether the mechanical properties development of SLM manufacturing maraging steel mold would be beneficial to improve the quality of mold.Design/methodology/approach - A series of block specimens and cylindrical tensile specimens are manufactured by SLM, and then are heat treated by solution treatment (ST) and solution treatment + aging treatment (ST + AT), respectively. The development of microstructure, microhardness and tensile strength of specimens is investigated. Then, a mold with conformal cooling channels is designed and manufactured by SLM and machined after ST with microhardness decreasing.Findings - The morphology of microstructure varies widely under different heat treatment. The microhardness and tensile strength decrease after ST with cellular structure broken, which is conducive to mechanical finishing for mold to improve surface accuracy. After that, the hardness and strength of the mold increase significantly by AT with the precipitation of Ni3Mo, Fe2Mo and Ni3Ti particles. The maraging steel mold with conformal cooling channels can be manufactured by SLM successfully. And the surface accuracy of mold could be improved easily by machining.Originality/value - ompared with the traditional mold with simple cooling channels, the mold with conformal cooling channels can be manufactured by SLM directly. The hardness of maraging steel mold manufactured by SLM can be reduced through ST, which is conducive to mechanical finishing for overcoming the defect of low precision of SLM directly manufacturing mold. This provides a new way for manufacturing mold of high quality.