Towards optimization of thickness, hardness, and porosity of low-pressure cold sprayed WC-Ni coatings

Abstract

In this study, a 3 3 full factorial design methodology was used to analyze the effects of spray parameters on the thickness, hardness, and surface porosity of low-pressure cold-sprayed WC-17Ni coatings. Three levels were selected for the spray parameters included in the design which were the powder feed rate (17.1 g/min, 21.1 g/min, and 23.7 g/min), gas temperature (475℃, 500℃, and 525℃), and the nozzle to substrate stand-off distance (3 mm, 5 mm, and 10 mm). It was found that the feed rate was the most signi cant parameter that affected the coating thickness. The surface porosity was most signi cantly affected by stand-off distance. The coating hardness was most in uenced by the interaction between the feed rate and stand-off distance. An optimization study was then performed to maximize the coating thickness and hardness while minimizing the surface porosity. The optimal spray parameters (OSP) were found to be at a feed rate of 23.7 g/min, 500℃ for the carrier gas temperature, and 10 mm for the standoff distance. The OSP yielded a coating that was 1.22 ± 0.06 mm thick, with a hardness of 364.5 ± 8.5 HV and porosity of 6.8 ± 0.6%. With a multi-parameter process, the system response is affected by both the variation in the individual parameters and the interaction of the parameters with each other. It was also concluded that the interaction between the parameters signi cantly affected the coating hardness. These results suggest that variation of the selected parameters produce statistically signi cant effects on the coating quality of WC-17Ni coatings using a low-pressure cold spray system.

Optimization of Cold Spray Process Inputs to Minimize Porosity and Maximize Hardness of Metal Matrix Composite Coatings on AZ31B Magnesium Alloy

“…In general, all parameters impact on the characteristics of the deposit. The prominent parameters 7 Journal of Nanomaterials that had a higher impact on the deposit were chosen based on previously published work [18,19]. The selected factors are temperature, SOD, and powder feed rate.…”

Sliding Wear Behavior of High-Temperature Vacuum-Brazed WC-Co-NiP Functional Composite Coatings

“…Although heavily studied, WC-Co particles continue to fascinate the research community, being recently found also as matrix material in carbon nanotubes [ 40 ] or in TiC-based hot-pressed composites [ 41 ]. The cermet particles are commonly incorporated in a matrix material, being very often deposited through various thermal spraying techniques such as plasma [ 40 , 41 ], cold gas [ 42 , 43 , 44 ], high-velocity oxy-fuel [ 35 , 45 , 46 , 47 ], air-fuel [ 48 , 49 , 50 ], spraying, or even by a process combining the last two [ 51 ].…”

Свойства Покрытий, Полученных Из Механически Обработанной Борсодержащей Смеси Порошков Методом Холодного Газодинамического Напыления

“…Многие работы посвящены получению композиционных покрытий методом холодного газодинамического напыления из порошковой смеси заданного состава (см., например, [2][3][4][5][6]). Традиционно подготовка композиционных смесей осуществляется с использованием вибростенда или V -образного смесителя.…”