基于焦耳热的滑压式增材制造方法温度场数值模拟与实验

Temperature Field Simulation and Experiment of Sliding-Pressure Additive Manufacturing Based on Joule Heat

摘要:

提出了一种针对小型金属零部件的低成本、高精度的焦耳热金属熔丝增材制造技术。在此过程中，系统温度场和热历史对于实验分析具有重要意义。本研究主要利用有限元仿真软件建立三维焦耳热金属熔丝增材制造的热-电-结构耦合有限元模型，分析了制造过程中温度场变化规律以及丝材内部和基板的温度分布和等温面形状。结果表明：焦耳热在丝材与滚轮之间产生，丝材内部在0.1 s内升温至2700 ℃，滚轮移动后，最大温度位置随着滚轮的移动而移动，丝材内部温度梯度呈拱形，基板温度梯度呈半椭球形。模拟结果的截面熔核区域与实验截面熔核区域吻合较好。因此，所建立的有限元模型能够较准确地模拟焦耳热熔丝增材制造过程温度场，对实验机理的研究和后期的进一步加工有着重要指导意义。

Abstract:

A sliding-pressure additive manufacturing technique with low cost and high accuracy based on Joule heat (SP-JHAM) was developed for the small metal parts. The temperature field and thermal history of the system are important for the experiment analysis. In this research, a thermal-electrical-structural coupling finite element simulation model for three-dimensional SP-JHAM process was established. The temperature field variation law during manufacturing, the temperature distributions inside the wire and substrate, and the shape of isothermal surfaces were analyzed. Results show that the Joule heat is generated between the wire and roller, and the internal temperature of wire rises to 2700 °C within 0.1 s. The position of the maximum temperature is moved with the roller moving. The temperature gradient inside the wire presents the arching shape, and that inside the substrate presents the semi-ellipsoidal shape. The simulated cross-section melting regions are in good agreement with the experimental ones. Thus, the established finite element model can accurately simulate the temperature field of SP-JHAM process, which is of great significance for the guidance of mechanism investigation and actual production.