Influence of deep cryogenic treatment of high speed steel substrate on TiAlN coating properties

Abstract

Deep cryogenic treatment in combination with classic heat treatment shows a significant improvement in wear resistance of high speed steel tools. The aim of this research was to investigate how the microstructure of the substrate tool steel material, which was altered by deep cryogenic treatment and plasma nitriding, influences the properties of TiAlN coating. The microstructure, topography and composition of the TiAlN coating were investigated using field-emission scanning electron microscope, atomic force microscopy, XRD, and glow discharge optical emission spectroscopy. The coating adhesion was measured using the scratch test. The sliding wear resistance and the force required to break the coating were determined with the ball-on-flat method. Resistance to microabrasion was measured by free ball abrasion test. The results show that deep cryogenic treatment combined with plasma nitriding influence the adhesion of the TiAlN coating to the high speed steel substrate. Wear resistance tests show better wear resistance of deep cryogenic treated samples in comparison with conventionally heat treated ones.Keywords: deep cryogenic treatment / plasma nitriding / PVD TiAlN coating / abrasive wear resistance / Die kryogenische Behandlung in Kombination mit der klassischen Behandlung zeigt eine wesentliche Verbesserung der Verschleißfestigkeit von Hochgeschwindigkeits-Werkzeugen an. Das Ziel dieser Arbeit war die Untersuchung der Mikrostrukturauswirkung des Werkzeugstahlsubstrats, das mit der kryogenischen Behandlung und mit dem Plasmanitrieren modifiziert wurde, auf die Eigenschaften der TiAlN Beschichtung zu zeigen. Die Mikrostruktur, die Topographie und die Zusammensetzung der TiAlN Beschichtung wurde mit FE, SEM, atomic force microscopy, XRD und glow discharge optical emission spectroscopy untersucht und analysiert. Die quantitative Beurteilung der Beschichtungsadhäsion wurde mit der Ritzprüfung durchgeführt. Der Gleitverschleiß und die benötigte Kraft mit der man die Beschichtung zerstören kann, waren mit der "Ball-on-Flat" Methode geprüft. Der Mikroabrasionswiderstand wurde mit dem Kalottenschliffverfahren gemessen. Die Resultate zeigen, dass die kryogenische Behandlung in Kombination mit dem Plasmanitrieren einen Einfluss auf die Adhäsion der TiAlN Beschichtungen an dem Hochgeschwindigkeits-Substrat hat. Die Gleitverschleißprüfungen zeigen bessere Resultate der kryogenisch behandelten Proben gegenüber den konventionell behandelten Proben.Schlüsselwörter: kryogenische Behandlung / Plasmanitrieren / PVD TiAlN Beschichtung / Charakterisierung / Gleitverschleißwiederstand /

Effect of Deep Cryogenic Treatment on Microstructure and Wear Resistance of LC3530 Fe-Based Laser Cladding Coating

“…The finer the grains of the cladding coating, and the more grains per unit volume, the more grains participated in resisting the deformation. As a result, the fine grains were not prone to microcracks in wear tests, thus improving the wear resistance of the surface [29,30,31]. This was why although the 24 HCT sample had the highest microhardness, the profile curve was similar to the 9 HCT and 12 HCT samples, because the 9 and 12 h samples had a better grain size and distribution.…”

Wear behaviour of TiAlN PVD coating on deep cryogenically treated HSS substrate

“…Standard TiAlN coating was deposited at the substrate temperature of 450 • C with a thickness of 6 µm using a magnetron sputtering process. The parameters and conditions of TiAlN coating deposition are described in detail in [5]. In the same work, detailed results of coating characterization are presented.…”

“…The images show TiAlN coating on the high-speed steel substrates and the uniform coating growth on both substrates. The results of the microstructure characterization of the coating with the mechanical and tribological properties of the coating are presented in [5].…”

“…Thin PVD coatings are due to fine-grained microstructures and large internal compressive strain more resistant to the formation of microcracks than CVD coatings. The efficiency of the PVD coated tools *Corresponding author: e-mail address: ssolic@unin.hr depends on the coating adhesion to the substrate and mechanical, thermal, and tribological properties of the coating itself but also on the properties of the workpiece material [1,[3][4][5].…”

“…Previous research has shown that the decisive importance for the efficiency of the tribo-system "substrate/coating/workpiece" belongs to the adhesion bond, i.e., the interface between the coating and the substrate material. The quality of the adhesion bond directly affects the performance of the coating in contact with the workpiece material and if the good adhesive bond is not achieved other coating properties are not revealed [1][2][3][4][5][6][7][8][9][10].…”