Machining Performance of Sputter-Deposited (Al0.34Cr0.22Nb0.11Si0.11Ti0.22)50N50 High-Entropy Nitride Coatings

Abstract

(Al0.34Cr0.22Nb0.11Si0.11Ti0.22)50N50 high-entropy nitride coatings prepared by reactive magnetron sputtering have been proved to have high hardness and superior oxidation resistance. Their thermal stability, adhesion strength, and cutting performance were investigated in this study. Hardness of the coating is 36 GPa, which only decreases slightly to 33 GPa after 900 °C annealing either in air or in vacuum for 2 h. No significant change in phase and microstructure were detected after annealing at 1000 °C. Rockwell C indentation and scratch tests shows that Ti interlayer provides a good adhesion between the nitride film and WC/Co substrates. In various milling tests, inserts coated with (Al0.34Cr0.22Nb0.11Si0.11Ti0.22)50N50 have evidently smaller flank wear depth than commercial inserts coated with TiN and TiAlN, even with their smaller thickness. Therefore, the (Al0.34Cr0.22Nb0.11Si0.11Ti0.22)50N50 coating has great potential in hard coating applications.

Adhesion and Mechanical Properties of TiAlN and AlTiN Magnetron Sputtered Coatings Deposited on the DMSL Titanium Alloy Substrate

“…Moreover, TiAlN is characterised by 21% higher value of elastic modulus as well as 16% higher value of microhardness than the AlTiN coating. As it can be seen on the average the TiAlN coating is harder and more rigid than the AlTiN coating and the mechanical properties of deposited coatings are comparable with the literature data [8,[23][24][25]. Besides that the obtained hardness results of PVD coatings deposited on the DMLS titanium substrate are in the range of those presented for coatings deposited on the bulk Ti-6Al-4V alloy, specified in [23].…”

“…Besides that the obtained hardness results of PVD coatings deposited on the DMLS titanium substrate are in the range of those presented for coatings deposited on the bulk Ti-6Al-4V alloy, specified in [23]. Furthermore, according to the literature [3,25], the H/E values (hardness/ elastic modulus) can be used as an indicator of the wear initiation. The higher H/E value indicates greater resistance to abrasion with higher hardness prior to smaller amount of residual steress.…”

“…The Rockwell test was conducted according to the VDI 3198 procedure in order to compare the films adhesion with the substrate. Accordingly to [21,22] the Rockwell indentation is classified into six ratings evaluating the damage degree from HF1 to HF6. HF1 to HF4 indicating adequate adhesion, and no evident spallation can be seen around the boundary.…”

“…In contrast, for HF5 and HF6, severe delamination took place which reflects inadequate adhesion between the film and the substrate. The parameters of test measurements are described in detail in [21,23]. Figure 2 illustrates the structures of AlTiN and TiAlN film surfaces The difference between films relies on its chemical composition (Table I).…”

Microstructure and Wear Behavior of FeCoCrNiMo0.2 High Entropy Coatings Prepared by Air Plasma Spray and the High Velocity Oxy-Fuel Spray Processes

“…Compared with the conventional alloys, the most distinguished effects in HEAs are high-entropy, severe lattice distortion, sluggish diffusion, and cocktail effects. These effects might provide several important advantages including ease of getting the supersaturated state and fine precipitates, an increased recrystallization temperature, slower grain growth, a reduced particle coarsening rate, and an increased creep resistance, which might be beneficial for high mechanical properties, superior thermal stability, and excellent wear-and corrosion-resistance [3,[5][6][7][8]. These outstanding properties were desirable for engineering applications, such as machinery, furnace parts, and even space [9].…”