Abstract Electron beam melting (EBM) is one of the promising technologies with the capability of producing complex near-net shapes from difficult to process materials such as titanium alloys. However, the parts produced from the EBM process suffer from the poor surface quality and machining is required to finish the EBM parts to achieve the necessary surface quality. Unlike the reported studies in the literature, the current study employs both uncoated, and PVD multi-coated (TiAlN/Al2O3/ZrCN) carbide inserts for the finishing of the electron beam melted γ-TiAl (Ti-48Al-2Cr-2Nb) and compares the machinability performance to identify the suitable type of the tool and the corresponding machining conditions. The obtained results indicate that the performance of the uncoated inserts is far superior as compared to the coated inserts in terms of producing lower tool wear and cutting forces, improved surface finish and morphology, and less subsurface microstructural and hardness alterations. The poor performance of the coated inserts is due to the high-temperature accumulation at the tool-workpiece interface due to the thermal shielding effect of the coatings, leading to severe built-up layer formation resulting in cascading effect of higher cutting forces, tool wear and oxidation, and poor workpiece surface integrity.

中文翻译：

---

关于使用涂层和未涂层​​刀具车削电子束熔化的 γ-TiAl：可加工性分析

摘要 电子束熔炼 (EBM) 是一种很有前景的技术，能够将钛合金等难以加工的材料制成复杂的近净形状。然而，EBM 工艺生产的零件表面质量较差，需要机加工来精加工 EBM 零件以达到必要的表面质量。与文献中报道的研究不同，目前的研究采用无涂层和 PVD ​​多涂层 (TiAlN/Al2O3/ZrCN) 硬质合金刀片对电子束熔化的 γ-TiAl (Ti-48Al-2Cr-2Nb) 和比较可加工性能，以确定合适的刀具类型和相应的加工条件。获得的结果表明，与涂层刀片相比，未涂层刀片的性能在​​产生更低的刀具磨损和切削力、改进的表面光洁度和形态以及更少的亚表面显微结构和硬度变化方面要优越得多。涂层刀片的性能不佳是由于涂层的热屏蔽作用在刀具-工件界面处高温积聚，导致严重的积屑层形成导致更高切削力的级联效应，刀具磨损和氧化，工件表面完整性差。