Nanocrystalline TiN coatings with improved toughness deposited by pulsing the nitrogen flow rate

Microstructures and properties of titanium nitride films prepared by pulsed laser deposition at different substrate temperatures

“…Additionally, the surface roughness of the film coupled with high hardness were critical for tribological performances [10], so the lowest roughness and the highest hardness might be another reasons for the TiN1 film which exhibited the lowest wear rate. The results were also in agreement with the theory [9,32] that the ratio of hardness and elastic modulus (H/E) was possible to evaluate the wear behavior of the films, in which the wear resistance of materials as a function of the H/E ratio, the maximum H/E ratio value correspond to the high anti-wear resistance, as shown in Fig. 7.…”

“…The hardness of films decreased with the increasing of substrate temperatures, while the hardness (22.5-30.6 GPa) was comparable to that of TiN films (17.3-26.7 GPa) [9], (12.7-27.2 GPa) [10] deposited by DC magnetron sputtering. However, which was lower than that of the TiN film deposited by PLD technique in available literatures (35-40 GPa) [18,27], where the TiN film deposited in some N 2 and CH 4 atmosphere.…”

“…The lowest friction coefficient reached to 0.088 for the TiN1 film, even if the friction coefficient of TiN4 film was less than 0.14 during the test. It was found that the friction coefficients were much lower compared to that of TiNx films ( ∼ 0.3) prepared by PLD in previous work [31], where the wear tests were performed with a Si 3 N 4 ceramic ball (3 mm in diameter) at a load of 0.98 N under the humid air (relative humidity 50%), and also lower than the DC magnetron sputtered TiN films with friction coefficients of 0.2-0.5, where [9] the wear tests were performed with a WC ball of 4 mm diameter at a load of 2 N under the same environment condition to our course. The friction coefficients of the deposited TiN films were stable during the wear tests, as shown in Fig.…”

“…In the past few decades, many researchers have studied the TiN films by a variety of film deposition techniques, including the physical vapor deposition (PVD) [3], chemical vapor deposition (CVD) [4,5], magnetron sputtering (MS) [6][7][8][9][10], ion implantation [11,12], thermal spraying [13,14] and so on. Compared with above methods, the pulsed laser deposition (PLD) technique [15][16][17] has proven to be rapid, efficient, easy operation and cost-effective in the fabrication of high-quality thin films.…”

Evaluation of fracture toughness of ZrN hard coatings by internal energy induced cracking method

“…Numerous techniques have been proposed to evaluate the fracture toughness of thin films, such as tension [2][3][4][5][6][7], bending [8][9][10], buckling [11] and indentation [12][13][14][15][16] tests, which can be categorized into stressbased and energy-based methods [17]. For the stress-based methods, the toughness is obtained by measuring stress intensity factor following the ASTM standards.…”