| WANG Feng,LIU Meng,LI Guo-he,WANG Da-chun,YAN Dong,FAN Jian-xun.Research Progress on Methods for Obtaining Constitutive Model of Metal Material Additive Manufacturing[J],52(3):52-63 |
| Research Progress on Methods for Obtaining Constitutive Model of Metal Material Additive Manufacturing |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.03.004 |
| KeyWord:additive/subtractive manufacturing constitutive model mechanical properties experiment hardness microstructure |
| Author | Institution |
| WANG Feng |
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin , China |
| LIU Meng |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , China |
| LI Guo-he |
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin , China |
| WANG Da-chun |
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin , China |
| YAN Dong |
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin , China |
| FAN Jian-xun |
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Additive/subtractive manufacturing is an advanced hybrid manufacturing technology that combines additive manufacturing with traditional machining. The additive forming materials have excellent mechanical properties and the forming process breaks the geometric constraints of the traditional machining. Therefore, the additive/subtractive manufacturing technology has a huge market prospect in the fields of aerospace, shipbuilding, and die manufacturing. However, the rapid cooling and heating in the additive process leads to the inhomogeneous of microstructure, which brings great challenges to the subsequent machining. Finite element simulation is an effective method to study the machining mechanism of additive manufacturing materials. The constitutive model is the decisive factor to assurance the accuracy of finite element simulation. Therefore, it is urgent to study on the establishment of constitutive relationship of additive manufacturing materials. The work aims to summarize the methods of obtaining the constitutive model of additive manufacturing of metal materials and review the research results of obtaining the constitutive model from five aspects of quasi-static test, hot compression test, dynamic test, hardness equivalence and microstructure simulation. The common methods used to study the mechanical properties of additive manufacturing materials by obtaining the stress-strain relationship and fit the corresponding constitutive model are the quasi-static test, hot compression test and dynamic test. On this basis, the existing problems were analyzed and the future development direction was prospected. On the aspect of quasi-static test, researchers in China and abroad have studied the mechanical properties of materials based on Ramberg-Osgood model, and put forward a variety of modified constitutive models. For hot compression test and dynamic test, researchers mostly use the Johnson-Cook model to characterize the dynamic mechanical properties of materials, and modify the model according to different test conditions and materials. The strain rate of quasi-static test is no more than 10–3 s–1, and that of hot compression test is 10–3~10 s–1. Compared with the high strain rate state of cutting process, there is still a large gap. Split Hopkinson pressure bar test is the most recognized method to obtain dynamic mechanical properties, which can obtain the stress-strain relationship of materials under high strain rate. However, the above three methods can only be used to study the mechanical properties of additive manufacturing materials based on the assumption of equivalent homogeneity. Due to the unique preparation process of additive manufacturing materials, their microstructure is not uniform, so the heterogeneity should be considered in the study of their mechanical properties. At present, the heterogeneous constitutive model can be constructed based on hardness equivalence and microstructure. Hardness equivalence method mainly fits the constitutive model of material equivalent relationship between hardness and stress. The direct hardness equivalence and nanoindentation test combined with finite element inverse method all can be used. Furthermore, the material inhomogeneity can be studied by combining the hardness distribution. However, this method is based on the empirical formula between hardness and stress and its accuracy cannot be guaranteed. The constitutive model based on microstructures is a comprehensive characterization of material mechanical properties by considering the microcosmic factors such as crystal size and shape, grain boundary, structural defects, dislocation slip, etc. However, the model is complicated and has too many parameters, which is still in the exploratory stage. The unique forming characteristics of additive manufacturing material make it more difficult to obtain the constitutive model compared with traditional materials. Although relevant researches have been carried out on the acquisition method of constitutive model for metal additive manufacturing and certain research results have been achieved. However, there are still significant deficiencies, and further research is urgently needed. According to the existing research, the problems of sample preparation, more attention should be paid to the model reliability and model application scope in the study of obtaining the constitutive model of additive manufacturing materials. In addition, nanoindentation experiment, which is widely used in weld seam research, is one of the effective methods to obtain mechanical properties of additive manufacturing materials because it can be used to study the heterogeneity of microstructure. |
| Close |
|
|
|