Thick CrN/NbN Multilayer Coating Deposited by Cathodic Arc Technique

Abstract

The production of tribological nanoscale multilayer CrN/NbN coatings up to 6 μm thick by Sputtering/HIPIMS has been reported in literature. However, high demanding applications, such as internal combustion engine parts, need thicker coatings (>30 µm). The production of such parts by sputtering would be economically restrictive due to low deposition rates. In this work, nanoscale multilayer CrN/NbN coatings were produced in a high-deposition rate, industrial-size, Cathodic Arc Physical Vapor Deposition (ARC-PVD) chamber, containing three cathodes in alternate positions (Cr/ Nb/Cr). Four 30 μm thick NbN/CrN multilayer coatings with different periodicities (20, 10, 7.5 and 4 nm) were produced. The coatings were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The multilayer coating system was composed of alternate cubic rocksalt CrN and NbN layers, coherently strained due to lattice mismatch. The film grew with columnar morphology through the entire stratified structure. The periodicities adopted were maintained throughout the entire coating. The 20 nm periodicity coating showed separate NbN and CrN peaks in the XRD patterns, while for the lower periodicity (≤10nm) coatings, just one intermediate lattice (d-spacing) was detected. An almost linear increase of hardness with decreasing bilayer period indicates that interfacial effects can dominate the hardening mechanisms.

The Effect of Macro-Particle Blocking Plate on the Morphology of Coated CrN Film by Arc Cathodic Evaporation Method

“…Thép không gỉ họ martensite như SUS420 thường được sử dụng làm một số dụng cụ như dao, kéo, khuôn ép nhựa,... nhờ đặc tính có tính chống ăn mòn tương đối tốt và có khả năng hóa bền bằng nhiệt luyện. Một số nghiên cứu đã áp dụng thêm các lớp phủ nitơrit nhằm nâng cao đặc tính bề mặt và khả năng bảo vệ cũng như tuổi thọ cho chi tiết làm từ thép không gỉ loại này [1][2][3][4]. Một trong các phương pháp thông dụng đó là sử dụng phương pháp hồ quang catôt để tạo ra môi trường plasma có nhiệt độ cao làm hóa hơi bia vật liệu kim loại như Cr, Ti hoặc Zr và ion hóa các kim loại trên cũng như các khí phản ứng đưa vào như nitơ để tạo ra các màng phủ hệ nitơrit có độ cứng cao cho các bề mặt được phủ bảo vệ [1].…”

Effect of periodicity on hardness and scratch resistance of CrN/NbN nanoscale multilayer coating deposited by cathodic arc technique

“…The total thickness of the multilayer coatings was kept within 20 and 25 μm in all cases. More details of the coating deposition are described by Araujo et al [21].…”

“…Previous work by the authors [21] have considered coatings deposited by a cathodic arc coating process (CAC), which is a technique that presents industrial interest, due to its high deposition rates when compared to sputtering. The CAC process allows the deposition of coatings with thicknesses above 25 mm, which is a value suitable to resist wear in many heavy-duty automotive engine applications.…”

Compositional and electrical properties of Cr, Nb, Cr/Nb, CrNbN, and CrN/NbN multilayers grown using the d.c. magnetron sputtering technique

“…Considering these two nitrides, some works have been developed to study the characteristics and properties of CrN/NbN systems. Most research activities have focused on mechanical, tribological, and corrosion resistance applications due to the outstanding chemical stability of NbN and hardness and corrosion resistance of CrN, and that superposition of performance can be achieved through a multilayer approach . Araujo et al showed that CrN/NbN multilayers can exhibit improved mechanical properties due to the coupling of different materials with a same crystalline structure, which interfaces can act as barriers for dislocation movements.…”

“…Most research activities have focused on mechanical, tribological, and corrosion resistance applications due to the outstanding chemical stability of NbN and hardness and corrosion resistance of CrN, and that superposition of performance can be achieved through a multilayer approach . Araujo et al showed that CrN/NbN multilayers can exhibit improved mechanical properties due to the coupling of different materials with a same crystalline structure, which interfaces can act as barriers for dislocation movements. Even though this bilayer system has shown favorable properties for metalworking and corrosion technological applications, studies focused on electrical properties can be an attractive research field in order to evaluate the superposition of high conductivity of NbN and the magnetic coupled semiconductor character of CrN.…”