Influence of heat treatment on the microstructure and performance of high-velocity oxy-fuel sprayed WC–12Co coatings

Improvement in Tribological Properties of Cr12MoV Cold Work Die Steel by HVOF Sprayed WC-CoCr Cermet Coatings

“…For the coatings, the wear rate increased from 3.58 × 10 −5 mm 3 •N −1 •m −1 at RT to 9.79 × 10 −5 mm 3 •N −1 •m −1 at 500 • C. Similarly for the die steels, the wear rate firstly increased from 9.76 × 10 −5 mm 3 •N −1 •m −1 at RT to 14.39 × 10 −5 mm 3 •N −1 •m −1 at 200 • C, then climbed sharply to 150.4 × 10 −5 mm 3 •N −1 •m −1 at 500 • C. These changes were mainly related to the content and distribution of oxides, as can be seen in detail in undermentioned worn surfaces analysis, as well as to the change of structures and mechanical properties [41]. The second reason for these changes may be that the hardness of the coating increased when test temperature increased from RT to 500 • C, whereas the fracture toughness showed the reverse tendency, resulting in the lowest wear resistance at 500 • C. This is similar to phenomenon reported by Wang et al [42]. The third reason is the change in contact geometry, which resulted in a low friction coefficient.…”

Mechanical property and wear performance dependence on processing condition for cold-sprayed WC-(nanoWC-Co)

“…For the cold-sprayed WC-(nanoWC-Co), the further increase in toughness during heat treatment contributes to a higher wear resistance, although the hardness tends to decrease a little. However, for HVOF-sprayed coatings, the heat treatment decreases the toughness and thereby leads to a lower wear resistance, which is consistent with literature [62].…”

“…13a and c that both as-sprayed and annealed HVOF microWC-12Co coatings present a micro-cutting weight loss mechanism. Due to the decomposition of WC particles and appearance of phase during the annealing treatment of HVOF-sprayed microWC-Co coating, the annealing treatment leads to a decrease of wear performance [57,58]. From this point of view, the cutting weight loss of WC-(nanoWCCo) coatings would lower than microWC-Co coating owing to a higher hardness.…”

“…14 (the data comes from both this study and literature). Compared to the HVOF-sprayed WC-Co coatings (and even newly developed warm sprayed coatings) [59][60][61][62], the cold-sprayed WC-(nanoWC-Co) presents obvious higher hardness and toughness. For the cold-sprayed WC-(nanoWC-Co), the further increase in toughness during heat treatment contributes to a higher wear resistance, although the hardness tends to decrease a little.…”

Sliding wear behavior of nanostructured WC–Co–Cr coatings

“…Mateen et al [4] suggested that the near-nanostructured WC-Co coating had a greater plasticity within the coating and, in contrast, the microstructured coating suffered from significant brittle fracture. In general, the failure of WC-Co coatings is always related with the following mechanisms: (i) delamination of coating, (ii) micro-cutting, (iii) fracture of carbides, cracks generated at the binder phase and disruption of the carbide-binder interfaces, (iv) extrusion of the binder phase and removal by plastic deformation and fatigue, and (v) undermining of the particles and subsequent particle pull-out [9][10][11][12][13].…”