Experimental Study and Mathematical Modeling of the Processes Occurring in ZrN Coating/Silumin Substrate Systems under Pulsed Electron Beam Irradiation

Nikolay N Koval,Elizaveta A Petrikova,Yurii F Ivanov,My Kim An Tran,Nikita A Prokopenko,Tamara V Koval,Anton D Teresov,Olga V Krysina,Pavel V Moskvin

doi:10.3390/coatings11121461

Nikolay N Koval, Elizaveta A Petrikova + Show 7 more

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https://doi.org/10.3390/coatings11121461

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Abstract

This paper presents a study of a combined modification of silumin, which included deposition of a ZrN coating on a silumin substrate and subsequent treatment of the coating/substrate system with a submillisecond pulsed electron beam. The local temperature on the samples in the electron-beam-affected zone and the thickness of the melt zone were measured experimentally and calculated using a theoretical model. The Stefan problem was solved numerically for the fast heating of bare and ZrN-coated silumin under intense electron beam irradiation. Time variations of the temperature field, the position of the crystallization front, and the speed of the front movement have been calculated. It was found that when the coating thickness was increased from 0.5 to 2 μm, the surface temperature of the samples increased from 760 to 1070 °C, the rise rate of the surface temperature increased from 6 × 107 to 9 × 107 K/s, and the melt depth was no more than 57 μm. The speed of the melt front during the pulse was 3 × 105 µm/s. Good agreement was observed between the experimental and theoretical values of the temperature characteristics and melt zone thickness.

Highlights

To control the properties of the surface layer of machine parts and mechanisms, various approaches are used that involve changing the elemental composition of the surface layer by ion implantation [1,2], ion mixing [3], and diffusion of alloying elements from gaseous [4,5], liquid [6,7] or solid [8,9] states
The aim of this work was to perform a combined modification of a eutectic silumin, including deposition of a ZrN coating on a silumin substrate and treatment of the coating/substrate system with a pulsed electron beam
ZrN coating/silumin substrate system with a ZrN-coating thickness of 0.5–2 μm resulted in a partial destruction of the coating, melting of the surface layer of the substrate, and emergence of the melt on tah(1e)s=u2rf4a,cae(2o)f=th1e24coating, which indicated that the coating was fuseρd, ktog tmhe–3substrate (Figure 2b–7d0)9. 0

Summary

Introduction

To control the properties of the surface layer of machine parts and mechanisms, various approaches are used that involve changing the elemental composition of the surface layer by ion implantation [1,2], ion mixing [3], and diffusion of alloying elements from gaseous [4,5], liquid [6,7] or solid [8,9] states. Examples of surface alloying are electro-explosive alloying [11,12] followed by pulsed electron beam treatment [13,14,15] and treatment of targets with pre-deposited films of alloying elements (aluminum, titanium, nickel, chromium, etc.) by compression plasma flows [16,17,18,19]. Such treatment produces remelted layers of a depth of up to 30 μm and a heat-affected zone of depth about 200 μm. It should be noted that this method, depending on the input energy density and the coating and substrate compositions, allows one to produce surface alloys of different compositions with the alloyed layer thickness from 0.1 to 100 μm [21,22,23] or to fuse single-layer hard coatings into lower melting point substrates to produce highly adhesive layers with enhanced properties [24,25]

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