ABSTRACT

Boronising is a thermochemical treatment which enhances the resistivity of metals used as component in applications dominated by wear and corrosion. In this study, boronising was performed on a gamma-TiAl intermetallic alloy with the pack cementation method. The experiments took place at temperatures 1173–1323 K for 8–14 h and a compact hard boride layer was formed. Its thickness varied between 6 and 25 μm. An 80 μm wide boron diffusion zone with elevated hardness was detected via micro-hardness measurements. The measured thickness values were applied to a mathematical model based on Fick’s second law of diffusion to extract the kinetic parameters of the process. Additionally, the presence of the ΤiΒ₂ and the total absence of the TiB phase were confirmed via XRD measurements. The hardness of the coating and the substrate was evaluated using Vickers micro-hardness tester (above 1100 HV at the coating layer).

摘要

渗硼是一种热化学处理，可提高金属的电阻率，该金属用作主要磨损和腐蚀的应用中的组件。在这项研究中，使用填充渗碳方法对 γ-TiAl 金属间合金进行了渗硼。实验在 1173-1323 K 的温度下进行 8-14 小时，并形成了致密的硬硼化物层。它的厚度在 6 到 25 μm 之间变化。通过显微硬度测量检测到 80 μm 宽的硼扩散区，硬度升高。将测得的厚度值应用于基于菲克第二扩散定律的数学模型，以提取过程的动力学参数。此外，TiΒ ₂的存在并且通过 XRD 测量确认完全不存在 TiB 相。使用维氏显微硬度计（涂层在 1100 HV 以上）评估涂层和基材的硬度。