STRUCTURE AND PROPERTIES OF Fe-B-C POWDERS ALLOYED WITH Cr, V, Mo OR Nb FOR PLASMA-SPRAYED COATINGS

Abstract

In the present study, the microstructure development and properties of the starting Fe-B-C powders for plasma spraying fabricated by dispersing a consumable rotating rod were investigated as functions of alloying elements additions. These powders were prepared in the following compositional ranges: B (10…14 wt.%), C (0.01…0.5 wt.%), Me (0…5.0 wt.%), where Me – Cr, V, Mo or Nb, balance Fe. Structural properties were characterized by etallography, X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Mechanical properties of the powders were measured by a Vickers indenter. Compression strength, oxidation resistance, and melting temperature were also determined. Chromium or vanadium were found to dissolve completely in Fe2(B, C) and Fe(B, C) constituent phases of the Fe-B-C powders replacing iron and forming substitutional solid solutions. By entering into the iron borides structure, these alloying elements improve ductility and oxidation resistance but lower melting temperature and hardness of the powders. Molybdenum or niobium were mainly found in secondary phases such as Mo2B, Mo2(B, C) or NbB2 at the Fe2(B, C) boundaries. As a result, these alloying elements enhance hardness, oxidation resistance and melting temperature of the powders.

Prediction of phase composition and mechanical properties Fe–Cr–C–B–Ti–Cu hardfacing alloys: Modeling and experimental Validations

“…Before welding coatings, due attention should be paid to the preparation of the surfaces of machine parts [ 18 ]. According to the condition of filler material deposition, the three most popular surfacing techniques utilized today are as follows: solution state (sole gel, electrochemical deposition [ 19 , 20 ], chemical solution deposition), gaseous state (ion beam-assisted deposition (IBAD), chemical vapour deposition (CVD)), physical vapour deposition (PVD) [ 21 , 22 ] and molten or semi-molten state (arc welding, plasma technology [ 23 , 24 ], spraying [ [25] , [26] , [27] , [28] ] and laser/electron beam [ 29 , 30 ]. Another issue is the shaping properties of surface layers to improve the tribological characteristic and wear resistance by various surface engineering methods including heat treatment [ 31 , 32 ] and thermochemical treatment (oxidation [ 33 , 34 ], carburizing, boriding, nitriding [ 35 ]) etc.…”

“…In addition, it is necessary to reduce the cost of filler materials and improve the hardfacing process efficiency In this connection, Fe–C–B system alloys being highly resistant to abrasive wear and having relatively low cost, become more widely spread [ 59 , 60 ]. Today, there are numerous investigations into simple ternary alloys of the Fe–C–B system [ [61] , [62] , [63] , [64] ], as well as additionally alloyed with a carbide-forming element [ 25 , [65] , [66] , [67] ] such as Cr [ 41 , [68] , [69] , [70] ], V, Nb, Mo [ 71 , 72 ], Ti [ 47 , 73 ], ferrite forming element (Al, Si) [ 58 , 73 ] and austenite forming element [ 74 ] (Cu [ 75 , 76 ], Ni, Mn). Boron can form the following compounds in these alloys: iron monoboride FeВ, hemioboride Fe 2 B, Fe 3 (B,C) and cubic boron carbide Fe 23 (C,B) 6 .…”

Physical-and-chemical processes at the interfaces of (Cu–Ni–Mn–Fe)/ (W–C) composites

“…To fabricate MMCs with enhanced properties, the processing technique must ensure a high volume fraction of reinforcement, its uniform distribution and acceptable adhesion between the matrix and the reinforcing phase without unwanted interfacial reactions that degrade the mechanical properties. Many processing tech-niques have been developed to produce MMCs employing a variety of binder and reinforcement combinations [6][7][8][9][10][11][12]. Among these, a spontaneous infiltration process is widely used for making MMCs with a high volume fraction of reinforcements which offers many more advantages compared to those of other conventional manufacturing processes [13][14][15][16].…”

Microstructure and Wear Characterization of the Fe-Mo-B-C—Based Hardfacing Alloys Deposited by Flux-Cored Arc Welding

“…The favorable combination of properties between the reinforced surface layer and the base metal can be achieved by using various surface engineering processes. Extension of the service life of critical parts is provided by the methods of hardening using surface deformation [ 40 , 41 ], electrochemical Cr plating [ 42 , 43 ], chemical-thermal treatment [ 44 , 45 ], electrospark doping [ 46 , 47 ], laser doping [ 48 , 49 , 50 ], laser cladding [ 51 ], plasma hardening [ 52 , 53 ], thermal spraying [ 54 , 55 ], supersonic spraying [ 56 , 57 , 58 ], vacuum-arc deposition [ 59 , 60 , 61 ], formation of oxide and nitride coatings by combined methods [ 62 , 63 , 64 , 65 , 66 , 67 ], manual arc hardfacing [ 68 , 69 ], and flux-cored arc welding [ 70 , 71 , 72 , 73 , 74 , 75 , 76 ].…”