SEM/TEM Investigation of Degradation of Bi-Layer (Cr,Al)N/Cr2N3 Duplex Coatings Exposed to AlSi Alloy High Pressure Die Casting Cycles

• Autorzy: Wilczek A. , Morgiel Jerzy , Sypień Anna , Pomorska Małgorzata , Rogal Łukasz

Identyfikatory

DOI

10.24425/amm.2022.141060

• Języki publikacji: EN

Abstrakty

EN

High pressure die casting (HDPC) allows to produce aluminum parts for car industry of complicated shapes in long series. Dies used in this process must be robust enough to withstand long term injection cycling with liquid aluminum alloys, as otherwise their defects are imprinted on the product making them unacceptable. It is expected that nitriding followed by coating deposition (duplex treatment) should protect them in best way and increase intervals between the cleaning/repairing operations. The present experiment covered investigations of the microstructure of the as nitride and deposited with CrAlN coating as well as its shape after foundry tests. The observations were performed with the scanning and transmission electron microscopy (SEM/TEM) method. They showed that the bottom part of this bi-layer is formed by roughly equi-axed Cr₂N crystallites, while the upper one with the fine columnar (CrAl)N crystallites. This bi-layers were matched with a set of 7x nano-layers of CrN/(CrAl)N, while at the coating bottom a CrN buffer layer was placed. The foundry run for up to 19 500 cycles denuded most of coated area exposed to fast liquid flow (40 m/s) but left most of bottom part of the coating in the areas exposed to slower flow (7 m/s). The acquired data indicated that the main weakness of this coating was in its porosity present both at the columnar grain boundaries (upper layer) as well as at the bottom of droplets imbedded in it (both layers). They nucleate cracks propagating perpendicularly and the latter at an angle or even parallel to the substrate. The most crack resistant part of the coating turned-out the bottom layer built of roughly equiaxed fine Cr₂N crystallites. Even application of this relatively simple duplex protection in the form of CrAlN coating deposited on the nitride substrate helped to extend the die run in the foundry by more than three times.

Słowa kluczowe

EN

duplex coatings; CrN/Cr2N/(CrN/CrAIN)/CrAlN; SEM; TEM; HPDC

• Wydawca: Institute of Metallurgy and Materials Science of Polish Academy of Sciences ; Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences
• Czasopismo: Archives of Metallurgy and Materials
• Rocznik: 2022
• Tom: Vol. 67, iss. 4
• Strony: 1341--1348
• Opis fizyczny: Bibliogr. 11 poz., fot., rys., tab.

Twórcy

autor

Wilczek A.

• Limatherm S.A., Tarnowska Str. 1, 34-600 Limanowa, Poland

autor

Morgiel Jerzy

• Institute of Metallurgy and Materials Science Polish Academy of Science, 25 Reymonta Str., 30-059 Krakow, Poland

• https://orcid.org/0000-0003-1807-0149

autor

Sypień Anna

• Institute of Metallurgy and Materials Science Polish Academy of Science, 25 Reymonta Str., 30-059 Krakow, Poland

• https://orcid.org/0000-0001-7601-1943

autor

Pomorska Małgorzata

• Institute of Metallurgy and Materials Science Polish Academy of Science, 25 Reymonta Str., 30-059 Krakow, Poland

• https://orcid.org/0000-0003-2220-2730

autor

Rogal Łukasz

• Institute of Metallurgy and Materials Science Polish Academy of Science, 25 Reymonta Str., 30-059 Krakow, Poland

• https://orcid.org/0000-0003-2289-8117

Bibliografia

• [1] A. Bavaro, D. Magistroni, Heat treatment of dies for pressure die casting: execution and tests, Metallurgia Italiana 6, 46-51 (2010).
• [2] P. Terek, L. Kovacevic, A. Miletic, P. Panjan, S. Balos, B. Skoric, D. Kakas, Effects of die core treatments and surface finishes on the sticking and galling tendency of Al-Si alloy casting during ejection, Wear 122-134, (356-357) (2016).
• [3] L. Kovacevic, P. Terek, A. Miletic, D. Kukuruzovic, B. Skoric, D. Kakas, P. Panjan, Industrial evaluation of duplex PVD hard coatings for HPDC, Journal of the Brazilian Society of Mechanical Sciences and Engineering 40, 271-278 (2018).
• [4] M. Oden, C. Ericsson, G. Hakansson, H. Ljungcrantz, Microstructure and mechanical behaviour of arc-evaporated Cr-N coatings, Surf. & Coat. Technology 114, 39-51 (1999).
• [5] K. Bobzin, T. Brogelmann, R.H. Brugnara, N.C. Kruppe, CrN/AlN and CrN/AlN/Al2O3 coatings deposited by pulsed cathodic arc for aluminium die casting applications, Surface and Coatings Technology 284, 222-229 (2015).
• [6] Y. Qiua, S. Zhangc, J.-W. Leed, B. Li, Y. Wangc, D. Zhaoa, Self-lubricating CrAlN/VN multilayer coatings at room temperature, Applied Surface Science 279, 189-196 (2013).
• [7] A. Wilczek, J. Morgiel, Ł. Rogal, W. Maziarz, J. Smolik, Microstructure and Wear of (CrN/CrAlN)/(CrAlN/VN) and (CrN/TiAlN)/(TiAlN/VN) Coatings for Moulds Used in High Pressure Casting of Aluminum, Coatings 10, 261, 1-11 (2020).
• [8] X-Z. Ding, X.T. Zeng, Y.C. Liu, J. Wei, P. Holiday, Influence of Substrate Hardness on the Properties of PVD Hard Coatings, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry 38, 156-161 (2008).
• [9] D.M. Sanders, A. Anders, Review of cathodic arc deposition technology at the start of the new millennium, Surface Coatings & Technology 133-134, 78-90 (2000).
• [10] J. Almera, M. Odena, G. Hakanssonb Microstructure, stress and mechanical properties of arc-evaporated Cr-C-N coatings, Thin Solid Films 385, 190-197 (2001).
• [11] A. Wilczek, J. Morgiel, Ł. Rogal, W. Maziarz, J. Smolik, Microstructure and wear of (CrN/CrAlN)/(CrAlN/VN) and (CrN/TiAlN)/(TiAlN/VN) coatings for moulds used in high pressure casting of aluminium, Coatings 10, 3, article no 261 (2020).

Uwagi

1. The research was carried out as a part of the “Implementation Doctorate” program of the Ministry of Science and Higher Education in Poland (Dz. U. poz. 873) 6/DW/2017/01/1.

2. Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).