Evaluation of Usefulness of AlCrN Coatings for Increased Life of Tools Used in Friction Stir Welding (FSW) of Sheet Aluminum Alloy

The study presents the results of examinations of wear in tools made of 1.2344 steel without and with an anti-wear coating in the process of welding overlap joints of sheet metal made of 7075-T6 aluminum alloy using friction stir welding (FSW) technology. A commercial anti-wear AlCrN coating (Balinit® Alcrona Pro by Oerlikon Balzers Coating Poland Sp. z o.o., Polkowice, Poland) was examined, applied using physical vapor deposition (PVD) and used to improve tool life in metalworking processes. Wear tests for the tools were conducted in industrial conditions at specific parameters of the friction stir welding process. Tool wear was evaluated through examination of the tool working surface. The results of the static tensile strength tests and metallographic examinations of the joints were used to evaluate the effect of tool wear and the coating impact on joint quality. The results obtained in the study show that the tool made of 1.2344 steel was intensively worn after the welding of a joint with the length of 200 m, increasing the risk associated with further use of the tool and suggesting the tool’s low durability. The use of the AlCrN coating led to an increase in tool life. The coating limits the process of tool wear and can be used as an anti-wear coating for tools used in the FSW of aluminum alloys.

The Research of the Wc-17co Abrasion-Resistant Coating by the D-Gun System on the Aluminium Alloy Substrate

This work use the D-gun system to spray the WC-17Co coating. analyzed the microstructure and performance of the coating by SEM, EDAX, XRD, HAXD. It gave a basis for the next research work for the anti-wear coating on aluminum alloy. The hardness of the WC-17Co coating is about HV1100~1300, the average porosity less than 1%. And the max diameter of the single hole is less than 0.012mm. There are no apparent oxide in the coating. The WC particles occurred decarburization during the spraying process and deposited the coating that composed with W2C and Co3W3C phases. The corrosion resistance of the coating is more ideal. But the phase distribution in the coating is not enough uniform.

Anti-Wear Coating Grown by Micro-Plasma Oxidation on Aluminum Alloys in the Solution of Aluminate-Titania

In this paper, Aluminum trioxide ceramic coatings were grown on surfaces of 2024 Aluminum alloys by micro-plasma oxidation in an aluminate electrolytic solution. In order to decrease the density of the pores and increase the anti-wear property of the ceramic coatings, Titania were added into the aluminate electrolytic solution. The struture and anti-wear property of the produced ceramic coatings were measured by X-ray diffraction, scanning electron microscope , hardness tester and frictionometer. The results show that the thickness of the ceramic coating is about 24±1 μm, surfaces of the ceramic coatings are very uniform. The hardness of the doped coating is up to 930 HV, and the wear property of the coating is the more excellent than that of undoped coating.

Development of Innovative Coating Technology, MSCoating, Using Electrical Discharge

MSCoating is a new coating technology using pulse discharge. This coating technology, which is developed by Mitsubishi Electric and IHI, has been put into practical use as an anti-wear coating for low-pressure turbine blades in aero engines. Normally, Z-notch, which is the edge of a low-pressure turbine blade in an aero engine, is treated with anti-wear coating by welding because these edges are frictioned together while the engine is running. However, coating by welding requires pre-heating, removal of excess thickness and advanced skill to ensure high reliability. Therefore, improvement of productivity and cost reduction are required for the anti-wear coating of Z-notch. MSCoating is an innovative coating technology that is able to meet these requirements. MSCoating can eliminate the above processing needed for coating by welding, and has superb productivity and reliability for machine work. It is confirmed that anti-wear performance of the coating formed by MSCoating is about 10 times as high as that formed by welding in a fretting wear test under conditions similar to the real operating condition. It is suggested that hard precipitate such as carbide and oxide of chrome and cobalt oxide in the MSCoating layer play a role in the advantages of the anti-wear performance.