Effects of Temperature on Wear Properties and Mechanisms of HVOF Sprayed CoCrAlYTa-10%Al2O3 Coatings and H13 Steel

Abstract

In this study, the CoCrAlYTa-10%Al2O3 coatings were prepared by the high-velocity oxygen-fuel (HVOF) spraying. A series of ball-on-disk sliding wear tests were conducted to evaluate the tribological properties of the coatings at different temperatures (25 °C, 200 °C, 400 °C, and 600 °C). The results showed that the average coefficients of friction (COFs) of the CoCrAlYTa-10%Al2O3 coatings were lower than that of H13 steel at different temperatures. The average COFs of the CoCrAlYTa-10%Al2O3 coatings and H13 steel both decreased with increasing temperature. The wear rate of the CoCrAlYTa-10%Al2O3 coatings increased first and then decreased. The microhardness of worn surface of the CoCrAlYTa-10%Al2O3 coatings increased with increasing temperature, while the microhardness of worn surface of H13 steel at 25 °C and 200°C was higher than that at 400 °C and 600 °C. The wear mechanism of the two materials was mainly abrasive wear. The tribofilms were formed on the worn surface of the CoCrAlYTa-10%Al2O3 coatings, which had a good protective effect. Due to thermal softening and low binding strength of debris, it was difficult for H13 steel to form the tribofilms. The wear rate of H13 steel was much higher than that of the CoCrAlYTa-10%Al2O3 coatings at 400 °C and 600 °C, indicating that the high temperature wear resistance of the coatings was much better than that of H13 steel.

A Review on the Enhancement of Mechanical and Tribological Properties of MCrAlY Coatings Reinforced by Dispersed Micro and Nanoparticles

“…Although the experiments reported in the literature state specific temperature values for conducting friction-wear tests, it must be noted that the experiencing temperature at the contact surfaces is higher due to the generated friction heat [88,179]. Moreover, change in the mechanical properties of the materials at high temperatures must be taken into consideration.…”

“…On the other hand, the addition of CeO 2 reduced the damage due to then oxidation wear mechanism, and a small number of fallen oxide particles were evident. Furthermore, a study by Wei et al [88] clarified the superior resistance of reinforced MCrAlY coatings in high-temperature friction-wear tests. In their research, CoCrAlYTa-10%Al 2 O 3 coatings were deposited by the HVOF technique, and their wear properties were examined through conducting ball-on-disk sliding experiments at a 25-600 • C temperature range.…”

High-Temperature Oxidation Behavior of Plasma-Sprayed CoCrAlTaY-30Al2O3 Cermet Coating at 1050 °C

“…Hou et al [10] prepared the CoCrAlYTaCSi-10%Al 2 O 3 cermet coating by high-velocity oxygen fuel (HVOF) and found that the addition of Al 2 O 3 ceramic could improve the hardness, elastic modulus, and wear resistance of the coating, and the wear rate of the coating at 600 • C and 800 • C was 3.96 × 10 −5 mm 3 /N•m and 2.58 × 10 −6 mm 3 /N•m, respectively. Wei et al [18,19] studied the friction and wear properties of HVOF CoCrAlYTA-10%Al 2 O 3 cermet coating under different loads and temperatures. A smooth tribofilm was formed in the worn area of the coating at 600 • C when the loads were lower than 9 N, while the tribofilms were broken as the load increased to 12 N. The average coefficient of friction of the coating decreased with an increase in temperature from 25 • C to 600 • C, while the wear rate of the coating first increased and then decreased.…”