Microstructural evolution of the rapidly quenched Fe–Cr–B alloy thermal spray coatings

Microstructural Characteristics and Tribological Behavior of HVOF-Sprayed Novel Fe-Based Alloy Coatings

“…Therefore, during spraying, carbides and borides are thought to dissolve into the surrounding Fe-rich matrix and subsequently the rapid quenching and solidification results in precipitation of fine-grained Cr-and B-rich compounds embedded into a metastable Fe-rich solid solution which is significantly supersaturated in solute elements. A similar microstructural evolution was previously described in thermally sprayed Fe-Cr-B [24]. Feedstock powder particles consisting of boride-based phases in a Fe-based matrix were indeed also found to turn into featureless lamellae, mainly consisting of a solid solution supersaturated in boron, as a consequence of melting and impact quenching.…”

Microstructure evolution and thermal stability of an Fe-based amorphous alloy powder and thermally sprayed coatings

“…Because these alloys transform from the liquid to the amorphous state at low critical cooling rates, and also possess relatively high glass transition and crystallization temperatures, the process conditions which exist in HVOF spraying can reportedly be sufficient to produce more than 50% amorphous phase; i.e. significantly greater than could previously be obtained with alloys of low GFA [7][8][9].…”

“…A number of researchers have investigated the deposition, by thermal spraying, of multicomponent Ni-Cr-B-C-and Fe-Cr-B-C-based alloys which form an amorphous structure when quenched from the melt at high cooling rates, i.e. in the region of 10 7 K s −1 [7][8][9]. Frequently, it has been found that when such alloys are deposited by the HVOF process the final coating contains only a relatively small fraction of the amorphous phase.…”

Effects of chromium addition on corrosion resistance of Fe–3.5B alloy in liquid zinc

“…XRD patterns (C4 and C5 samples shown in Fig. 2) also indicate the presence of many M 2 B-type eutectic borides (M represents both Fe and Cr, namely (Fe, Cr) 2 B) in the as-cast Fe-3.5B alloy [15,[24][25][26][27], such as Cr 1 chromium concentration ranges from 0 wt.% to 5 wt.%, the corrosion depth decreases, namely, the corrosion rates decrease and the corrosion resistance of Fe-3.5B alloys to liquid zinc enhances sharply (shown in Fig. 3(a) and (b)).…”