Fatigue and Mechanical Behavior of Ti-6Al-4V Alloy with CrN and TiN Coating Deposited by Magnetic Filtered Cathodic Vacuum Arc Process

Abstract

Coatings of 3 μm CrN and TiN were prepared by a magnetic filtered cathodic vacuum arc process (MFCVA) on Ti-6Al-4V substrates, respectively. Rotating bending tests and uniaxial tests were conducted for investigating the effect of the thin and uniformly distributed hard CrN and TiN coatings on the fatigue and mechanical properties of Ti-6Al-4V substrate. During both tests, no coating spallation phenomenon was observed, which indicated that the hard coating bound well with the substrate. The fatigue test results showed that the fatigue strength of the coated sample was decreased in both the low- and high-cycling fatigue regimes compared with the uncoated Ti-6Al-4V substrate. Compared with the TiN coating, the CrN coating caused a more significant reduction on the fatigue property of the uncoated Ti-6Al-4V substrate due to its inferior plastic deformation capacity. Furthermore, the tensile test results showed that the coated sample had a relative higher ultimate strength, yield strength, and lower elongation compared with the uncoated Ti-6Al-4V substrate. This may be due to the fact that the hard coating could suppress the initiation of cracks, and so higher stress was needed for crack initiating. During the crack propagation period, the hard coating cracked at a relative higher velocity, which led to cracking of the ductile substrate and elongation reduction.

Research on Cleaning Mechanism of Anti-Erosion Coating Based on Thermal and Force Effects of Laser Shock

“…These substrates were then cleaned in an ultrasonic cleaner with acetone for 15 min and dried with alcohol before deposition. And the deposition parameters of the TiN coatings are shown in Table 2 [30]. Table 2.…”

Investigations in Anti-Impact Performance of TiN Coatings Prepared by Filtered Cathodic Vacuum Arc Method under Different Substrate Temperatures

“…Afterwards, all the samples were ultrasonically cleaned with acetone for 15 min and dried in the pure N 2 atmosphere. As shown in Figure 1 [32], the coating deposition equipment mainly consists of ion implantation source and FCVA apparatus with a metal vapor vacuum arc (MEVVA) source. It should be noted that the ion implantation source here was used to improve the adhesion strength for TiN coatings [24,33].…”

Effect of Ar/N2 flow ratio on the microstructure and mechanical properties of Ti-Cr-N coatings deposited by DC magnetron sputtering on AISI D2 tool steels

“…Binary hard coatings of metal nitrides like TiN and CrN are commonly used as protective coatings in industry because of their high hardness, low friction coefficient and their ability to extend tool life during abrasive and chemical aggressive conditions [1,2]. However, the performance and reliability of these nitrides do not meet the requirements for specific applications such as in high speed machining, dry cutting, drilling and jet engine turbine blades [3].…”