基于有限元的长轴杆件硬质涂层的热应力研究

Study on Thermal Stress of Hard Coating of Long Axis Bar Based on Finite Element

摘要: 长轴杆件零部件因其结构的特殊性在表面硬质涂层的制备过程中受到一定限制。本文利用有限元模拟计算了长轴杆件表面Ti系涂层在600℃环境温度范围内杆件的热应力变化及涂层厚度对基体和涂层的影响。结果表明：在涂层制备过程中，杆件热应力在两端会出现应力集中，且随着温度上升，应力逐渐向杆件中间部分扩散，温度稳定后，应力集中现象逐渐消失；基体两端表面随着温度上升，出现中心应力低于四周应力的现象，使用的四种Ti系涂层材料中TiAlN涂层的热应力最大，为74.02 MPa，Ti的热应力最小，为38.01 MPa。涂层厚度的增加，在5~9 μm范围内，TiAlN涂层的热应力变化不明显。

Abstract: Due to the particularity of its structure, long axis bar parts in the surface hard coating preparation process are limited. In this paper, the thermal stress variation of Ti-based coating on the surface of long axis bar in 600˚C ambient temperature is calculated and the influence of coating thickness on the substrate and coating is simulated by finite element method. The results show that during the coating preparation process, the thermal stress of the rod will be concentrated at both ends, and as the temperature rises, the stress gradually diffuses to the middle part of the rod. After the temperature is stable, the stress concentration phenomenon gradually disappears. With the increase of temperature at both ends of the substrate, the central stress is lower than the surrounding stress. Among the four Ti-based coating materials used, the thermal stress of TiAlN coating is the largest, 74.02 MPa, and the thermal stress of Ti is the smallest, 38.01 MPa. With the increase of coating thickness, the thermal stress of TiAlN coating does not change obviously in the range of 5~9 μm.