High Temperature Erosion-oxidation Resistance of Thermally Sprayed Nanostructured Cr3C2-25(Ni-20Cr) Coatings

Abstract

This study reports the high temperature erosion-oxidation (E-O) behavior of conventional and nanostructured Cr 3 C 2 -25(Ni-20Cr) coatings prepared by high velocity oxygen fuel (HVOF) spraying. As-received and nanostructured Cr 3 C 2 -25(Ni-20Cr) powders with mean crystallite sizes of 145 nm and 50 nm respectively, were used to prepare 120 -200 μm thick coatings on AISI 310 samples. The E-O behavior of the coatings prepared with the as-received (AR) and nanostructured (NS) powders was determined as weight change in a custom designed rig at room temperature, 450, 700 and 800 ºC. The Vickers microhardness, Young's Modulus and fracture toughness of the AR and NS coatings were determined, and the NS coatings exhibited higher values compared with the AR coatings. The E-O resistance of the NS coating was higher than that of AR coating at all temperatures, and particularly at 800 ºC. The increase in E-O resistance of the NS coatings is due to its superior mechanical properties as well as to the presence of some heterogeneities in the AR coatings. The E-O mechanisms of both types of the coatings are discussed, with special attention to that at high temperatures. The results suggest that at 800 ºC the E-O process is controlled by erosion of the oxide.

Optimization of Mechanical Properties of Cr3C2-Ni20Cr/Graphite Cold Sprayed Coatings

“…The Taguchi method is a tool used to optimize various processes in industry [19][20][21], including cold spraying [22][23][24]. In this paper, we experimented using the base powder Cr 3 C 2 -25(Ni20Cr), which has been used for many years to deposit wear-resistant coatings, mainly via HVOF spraying [25][26][27]. Several studies have also been carried out on the properties of these coatings deposited by means of cold spraying [28][29][30].…”

Comparative study of the fatigue performance of the micro and nanometric Cr3C2-25NiCr coating sprayed by HVOF on ASTM A516 steel substrate

“…Therefore, it can be assumed that the nanometric powder may consist of amorphous structures and crystal dispersions. The XRD analysis ( Figure 2 ) explains the presence of Cr 3 C 2 [13,15,20,27,29], and Cr 7 C 3 in the micrometric powder. The intensity of the peaks decreases, while they expand as a function of milling time.…”

Nd:YVO4 Laser Irradiation on Cr3C2-25(Ni20Cr) Coating Realized with High Velocity Oxy-Fuel Technology—Analysis of Surface Modification

“…Cr 3 C 2 -25 coatings have been widely used in high-temperature (850 • C) industrial applications due to their structural stability and retention of mechanical properties at higher service temperatures [22]. A variety of techniques can be used to prepare chromium carbide-based coatings, among which HVOF processes have been widely used, as they produce smooth, low-porosity, dense, and adherent coatings, without significantly altering the integrity of the carbide particles [23]. Some preliminary studies presented in the literature that focus on laser surface modification of carbide coatings are detailed in the following: Morimoto et al tested the effect of a diode laser on a cermet coating, achieving an increase in surface hardness [24]; Sun et al, using a fiber laser, tested the effect of scan speed on wear behavior and observed that the wear resistance of the optimized layer was increased by 29.76 times [25].…”