Surface Modification of Grey Cast Iron by Pulsed-plasma Deposition and Subsequent Laser Beam Melting

Authors Yu.G. Chabak1 , V.G. Efremenko1 , V.I. Fedun1 , I. Petryshynets2, T.V. Pastukhova1 , B.V. Efremenko1, F. Kromka2, E.V. Tsvetkova1

1Pryazovskyi State Technical University, 7, Universitetskaia St., 87555 Mariupol, Ukraine

2Institute of Materials Research, Slovak Academy of Sciences, 04001 Kosice, Slovakia

Issue Volume 13, Year 2021, Number 2
Dates Received 01 December 2020; revised manuscript received 15 April 2021; published online 20 April 2021
Citation Yu.G. Chabak, V.G. Efremenko, V.I. Fedun, et al., J. Nano- Electron. Phys. 13 No 2, 02030 (2021)
PACS Number(s) 52.77. – j, 62.20.Qp, 61.66.Dk, 64.70.Kb
Keywords Pulsed-plasma deposition, Composite coating, Laser melting, Microstructure (21) .

The object of this work is to study the microstructure and wear behavior of grey cast iron superficially modified by pulsed-plasma deposition of the coating and subsequent laser beam melting. The coating 50 vol. % WC + 50 vol. % Al-bronze of 85-135 μm width was deposited employing an electrothermal axial plasma accelerator with ten pulses under the discharge voltage of 4 kV. The coated surface was subsequently melted by infrared fiber laser TruFiber 400 (TRUMPF) with a beam wavelength of 1064 nm (beam spot was 0.5 mm, scanning velocity was 0.5 mm·s – 1, power was 400 W). The investigations included scanning electron microscopy observation (JSM-6510 JEOL), energy-dispersive X-ray spectroscopy (JED-2300, JEOL), tribological testing (tribometer Micron-tribo) and microhardness measurement (FM-300, Future-Tech Corp.) under the load of 0.05 kg. After the deposition/laser melting to a depth of up to 600 μm, the surface was modified from ferrite/lamellar graphite structure to Ledeburite-like eutectic/ε-copper precipitates structure. The carbide eutectic consisted of fine pearlitic dendrites embedded into a cementite matrix. The structural gradient from fully remelted zone to transitional (carbide/graphite) zone and further to heat-affected zones (with pearlite and ferrite/pearlite matrix structure) was revealed in the cross-section to reach 1250 μm in total width. The microhardness of the remelted zone was measured as 900-1000 HV50 to be 5 times higher than that of unmodified structure. The double surface treatment increased the scratch wear resistance of a modified grey cast iron by 15 times as compared to the ferrite/graphite substrate. The effect of copper and tungsten on laser-induced structure formation in grey cast iron is discussed.

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