A comparative study of microstructure, oxidation resistance, mechanical, and tribological properties of coatings in Mo–B–(N), Cr–B–(N) and Ti–B–(N) systems

Сытченко

Kaplanskii

et al. 2021

Metals

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °С temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-В-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °С) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Structure, Corrosion Resistance, Mechanical and Tribological Properties of ZrB2 and Zr-B-N Coatings

Сытченко

Kaplanskii

et al. 2021

Metals

“…Причиной может служить формирование в покрытиях MoSiB дополнительной аморфной фазы на основе MoB [28]. Надо, однако, заметить, что нанокристаллическим покрытиям MoB присущи достаточно высокие механические характеристики (Н = 27 ГПа, Е = 330 ГПа) [47]. Многослойные покрытия MoSiB/SiBC обладали следующими свойствами: H = 23÷27 ГПа, E = 301÷351 ГПа, W = = 53÷56 %, H/E = 0,076÷0,077, H 3 /E 2 = 0,134÷0,160 ГПа.…”

Section: структураunclassified

Structure, Mechanical Properties, and Oxidation Resistance of MoSi2, MoSiB, and MoSiB/SiBC Coatings

Russ. J. Non-ferrous Metals

Potanin

2018

Методом магнетронного напыления получены однослойные покрытия MoSi 2 , MoSiB и многослойные MoSiB/SiBC. Структура покрытий исследована с применением рентгенофазового анализа, растровой электронной микроскопии и оптической эмиссионной спектроскопии тлеющего разряда. Механические свойства покрытий определены с помощью метода наноиндентирования. Исследованы термическая стабильность покрытий в диапазоне температур 600-1200 °С и жаростойкость при нагреве до 1500 °С. Установлено, что однослойные покрытия MoSiB обладают твердостью 27 ГПа, модулем упругости 390 ГПа и упругим восстановлением 48 %, а также могут кратковременно сопротивляться окислению до температуры 1500 °С включительно, что обусловлено формированием на их поверхности защитной пленки на основе SiO 2 . Покрытия MoSi 2 имеют твердость, сравнимую с твердостью покрытий MoSiB, но несколько уступают им по жаростойкости. Многослойные покрытия MoSiB/SiBC характеризовались твердостью 23-27 ГПа и жаростойкостью, ограниченной 1500 °С, но при этом обладали более высокими упругопластическими характеристиками по сравнению с MoSiB.

“…The closest analogs are coatings Zr-Si-B and Mo-Si-B, which were previously deposited by magnetron sputtering [ 5 , 8 , 25 , 30 , 31 , 32 ]. It should be noted that the properties of the coatings (in particular, tribological performance) can be greatly enhanced by the introduction of nitrogen into the coating via the sputtering in the nitrogen atmosphere [ 33 , 34 ].…”

Section: Introductionmentioning

confidence: 99%

Structure and Properties of Zr-Mo-Si-B-(N) Hard Coatings Obtained by d.c. Magnetron Sputtering of ZrB2-MoSi2 Target

Сытченко

Pogozhev

et al. 2021

Materials

Coatings in a Zr-Mo-Si-B-N system were deposited by the magnetron sputtering of ZrB2-MoSi2 targets in argon and nitrogen. The structure of the coatings was investigated using scanning electron microscopy, X-ray diffraction, energy-dispersive spectroscopy, and glow-discharge optical emission spectroscopy. Mechanical and tribological properties were measured using nanoindentation and pin-on-disc testing. Oxidation resistance and oxidation kinetics were estimated via annealing in air at 1000–1500 °C and precision weight measurements. We found that the coatings deposited in Ar demonstrate a superior combination of properties, including hardness of 36 GPa, elastic recovery of 84%, a friction coefficient of 0.6, and oxidation resistance at temperatures up to 1200 °C. High oxidation resistance is realized due to the formation of the protective (SiO2 + ZrO2)/SiO2 oxide layer, which inhibits the diffusion of oxygen into the coating.