Investigations on the Surface Integrity and Wear Mechanisms of TiAlYN-Coated Tools in Inconel 718 Milling Operations

Francisco J G Silva; Naiara P V Sebbe; Rúben D F S Costa; André F V Pedroso; Rita C M Sales-Contini; Marta L S Barbosa; Rui P Martinho

doi:10.3390/ma17020443

Investigations on the Surface Integrity and Wear Mechanisms of TiAlYN-Coated Tools in Inconel 718 Milling Operations

Materials (Basel). 2024 Jan 17;17(2):443. doi: 10.3390/ma17020443.

Authors

Francisco J G Silva^{1

2}, Naiara P V Sebbe^{1

3}, Rúben D F S Costa^{2

3}, André F V Pedroso^{1

3}, Rita C M Sales-Contini^{1

4}, Marta L S Barbosa³, Rui P Martinho¹

Affiliations

¹ ISEP, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida, 4249-015 Porto, Portugal.
² Associate Laboratory for Energy, Transports and Aerospace (LAETA-INEGI), Rua Dr. Roberto Frias, 400, 4200-465 Porto, Portugal.
³ Department of Mechanical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 400, 4200-465 Porto, Portugal.
⁴ Technological College of São José dos Campos, Centro Paula Souza, Avenida Cesare Mansueto Giulio Lattes, 1350 Distrito Eugênio de Melo, São José dos Campos 12247-014, Brazil.

Abstract

Inconel 718 is a Ni superalloy with superior mechanical properties, even at high temperatures. However, due to its high hardness and low thermal conductivity, it is considered a difficult-to-machine material. This material is widely used in applications that require good dimensional stability, making the milling process the most used in machining this alloy. The wear resulting from this process and the quality of the machined surface are still challenging factors when it comes to Inconel 718. TiAlN-based coating has been used on cutting tools with Yttrium as a doping element to improve the process performance. Based on this, this work evaluated the machined surface integrity and wear resistance of cutting tools coated using Physical Vapor Deposition (PVD) HiPIMS with TiAlYN in the end milling of Inconel 718, varying the process parameters such as cutting speed (v_c), feed per tooth (f_z), and cutting length (L_cut). It was verified that the L_cut is the parameter that exerts the most significant influence since, even at small distances, Inconel 718 already generates high tool wear (TW). Furthermore, the main wear mechanisms were abrasive and adhesive wear, with the development of a built-up edge (BUE) under a125 m/min feed rate (f) and a L_cut = 15 m. Chipping, cracking, and delamination of the coating were also observed, indicating a lack of adhesion between the coating and the substrate, suggesting the need for a good interlayer or the adjustment of the PVD parameters.

Keywords: HiPIMS technique; Inconel 718; TiAlYN coatings; milling; surface integrity; tool wear mechanisms.

Grants and funding

The work is developed under the “DRIVOLUTION—Transition to the factory of the future”, with the reference DRIVOLUTION C644913740-00000022 research project, supported by European Structural and Investments Funds with the “Portugal2020” program scope.