Enhanced erosion performance of cold spray co-deposited AISI316 MMCs modified by friction stir processing

Abstract

The present study reports on the erosion properties of a novel surface engineering process combining cold spray and friction stir processing. Tungsten carbide (WC-CoCr) and aluminium oxide (Al2O3) powders were cold spray co-deposited with AISI316 using a twin powder feed system. The deposited coatings were subsequently friction stir processed to refine and redistribute the reinforcing particles and remove the coating-to-substrate interface layer, thus generating a new metal matrix composite surface. Microstructural analysis of the SprayStirred (cold sprayed then friction stirred) specimens revealed significant particle refinement and improved particle distribution over the as-deposited coatings. The erosion performance of these SprayStirred surfaces was evaluated using a flowing slurry and demonstrated an 80% decrease in volume loss over the as-received AISI316 at 30° angle of attack. For SprayStirred WC-CoCr, microhardness measurements indicated an increase of approx. 530% over the unaltered AISI316 and 100% over the cold sprayed coating. These findings highlight the considerable increase in erosion performance of the SprayStirred specimens, and thus demonstrate the benefits of this innovative surface engineering process. This outcome is attributed to dispersion strengthening, imparted by the refined tungsten carbides. Furthermore, the SprayStirred WC-CoCr coating exhibited an 85% reduction in volume loss over an HVOF sprayed WC-CoCr coating

Post-Process Treatments on Supersonic Cold Sprayed Coatings: A Review

“…Coatings 2020, 10, 123 9 of 35 break up or dissolve the secondary phase particles in the cold sprayed metal matrix composite (MMC) deposits, leading to considerable improvement in mechanical properties. Incorporating cold spray with FSP is a novel two-stage surface engineering process referred to as 'SprayStir' [56,57]. Table 2 summarizes the previous studies regarding the effects of post FSP on cold sprayed coatings.…”

“…In this case, the FSP parameters should be tailored to better modify the microstructures of cold sprayed MMC coatings. For example, when the rotation speed increased from 900 rpm to 1200 rpm and 1500 rpm, the refinement became more prominent with less ceramic particles visually [57]. Moreover, additional FSP passes through the MMC coatings could also distribute the cold sprayed reinforcing ceramic particles to a greater extent, even to nanoscale [61].…”

“…Moreover, additional FSP passes through the MMC coatings could also distribute the cold sprayed reinforcing ceramic particles to a greater extent, even to nanoscale [61]. The refined and uniformly dispersed ceramic particles after FSP can have a positive effect on the strengthening of the metal matrix coatings [57]. Al2O3; and (f) spray stirred Al2O3 (adapted from reference [56], with permission from © Elsevier).…”

Cold Sprayed Tungsten Armor for Tokamak First Wall

“…Even then, the studies employing such concept are limited in the literature and involve successful depositions of W-Cu by Kang and Kang [10] and Deng et al [11], W-Ni-Fe by Xia et al [12], and low tungsten content in W-90Ta coatings by Barnett et al [13] only. Considering their excellent wear properties, a significantly broader series of studies involved the research of cemented carbides in a form of WC-Co [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], WC-Ni [32][33][34][35][36][37][38][39][40][41], WC-Co-Ni [42], WC-Co-Cr [31,[43][44][45], or WC-Cu-MoS 2 [46,47]. Unfortunately, the carbides could not be used for PFCs and so we could not built on these results.…”

Functionally Gradient Coating of Aluminum Alloy via In Situ Arc Surface Nitriding with Subsequent Friction Stir Processing

“…They found that the Al 2 O 3 particles uniformly distributed inside the substrate, which exhibited low coefficient of friction (COF) and wear rate. Peat et al reported that the wear and erosion performances of a cold sprayed metal matrix composites (MMCs) were significantly improved after FSP. Yang et al used FSP to modify a cold sprayed AA2024/Al 2 O 3 MMCs, and stated FSP notably improved the refinement and dispersion of the Al 2 O 3 particles.…”