Microstructure and properties of Fe-based composite coating by laser cladding Fe–Ti–V–Cr–C–CeO2 powder

Zhou

et al. 2017

Metals

Abstract:The effect of laser cladding on the surface microstructure and corrosion properties of coated/uncoated specimens were investigated. Fe-based alloy coating was produced on 35CrMo steel by laser cladding. The phase composition, microstructure, interface element distribution, microhardness and corrosion resistance of the cladding coating were measured. The results show that the cladding layer is mainly composed of α-Fe phases, the microstructure presents a gradient distribution, and a good metallurgical bond is formed at the boundary with the substrate. Microhardness profiles show that the average microhardness of the cladding coating is about 2.1 times higher than that of the uncoated specimen. In addition, the electrochemical results show that the coated specimen exhibits far better corrosion resistance than to the uncoated specimen.

Section: Electrochemical Impedance Spectroscopymentioning

confidence: 95%

Microscopic Analysis and Electrochemical Behavior of Fe-Based Coating Produced by Laser Cladding

Zhou

et al. 2017

Metals

“…It should be noted that Cr in the melt favors the formation of chromium carbides rather than Fe 3 C because Cr has a stronger affinity to form carbides than iron [17]. Besides, the high cooling rate in PTA process increases the solubility of alloy elements in the matrix [5], thereby rendering superfluous alloy to form carbide solid solutions [18] such as Mo 2 V 4 C 5 and Ti 0.42 V 1.58 C. It is noteworthy that martensite and retained austenite were also detected. Along with XRD analysis, TEM was further employed to identify VC.…”

Section: Phase Structurementioning

confidence: 99%

Hard-yet-tough high-vanadium high-speed steel composite coating in-situ alloyed on ductile iron by atmospheric plasma arc

2017

Hard-yet-tough high-vanadium high-speed steel composite coating in-situ alloyed on ductile iron by atmospheric plasma arc Cao, Huatang; Dong, Xuanpu; Pei, Yutao T. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. H. Cao, et al., Int. J. Comp. Meth. and Exp. Meas., Vol. 6, No. 3 (2018) ABSTRACT A graded high-vanadium alloy composite coating was synthesized from premixed powders (V, Cr, Ti, Mo, Nb) on ductile iron (DI) substrate via atmospheric plasma arc surface alloying process. The resulted cross-section microstructure is divided into three distinct zones: upper alloyed zone (AZ) rich with spherical primary carbides, middle melted zone (MZ) with fine white iron structure and lower heat affected zone (HAZ). Spherical or bulk-like primary carbides with diameter < 1 μm in the AZ are formed via in-situ reactions between alloy powders and graphite in DI. Microstructural characterizations indicate that the carbides are primarily MC-type (M=V, Ti, Nb) carbides combined with mixed hardphases such as M 2 C, M 7 C 3 , M 23 C 6 , and martensite. Disperse distribution of spherical, submicron-sized metal carbides in an austenite/ledeburite matrix render the graded coating hard-yet-tough. The maximum microhardness of the upper alloyed zone is 950 HV 0.2 , which is five times that of the substrate. Significant plastic deformation with no cracking in the micro-indentations points to a high toughness. The graded high-vanadium alloy composite coating exhibits superior tribological performance in comparison to Mn13 steel and plasma transferred arc remelted DI.

“…In-situ synthesized ceramic particle has characters of small size, uniformed distribution and good bonding with metal matrix. Recently, numerous in-situ synthesized ceramic phases have been studied, such as nitrides, 5) borides, 6,7) carbides, 8,9) Ti-Al intermetallics, 10) Ti-Si compounds 11) et al For Ti alloy, TiB is considered as the excellent ceramic reinforcing particle, because it has compatible physical and thermodynamic properties, high hardness (27 Gpa), same Young's modulus of elasticity with Ti and its alloy. 12,13) Besides, TiN shows higher plastic deformation than TiB at high temperature.…”

Section: Introductionmentioning

confidence: 99%

“…15,16) However, the morphology and distribution of reinforced phases play an important role on physical properties, which mainly depends on the crystal structure and solidification behavior, especially for the in-situ reinforced particles. Furthermore, laser cladding has a high cooling rate as fast as 10 6°C /s, its solidification process is different with equilibrium solidification.…”

Section: Introductionmentioning

confidence: 99%

Growth Morphology and Solidification Behavior of <i>In-Situ</i> Synthesized TiN and TiB

Huang

Zhu

et al. 2016

Mater. Trans.

Titanium-based composite coating reinforced by in situ synthesized TiN and TiB particles was successfully fabricated on Ti-3Al-2V alloy by laser cladding with Ti/c-BN powder mixture. The microstructures of in situ synthesized TiB and TiN were compared with needle platelet and dendrite. TiB tends to nucleate and grow on the surface of TiN and grain boundary. In the rapid solidification process, phases crystallization follow the five steps: primary TiN ¼ peritectic structure TiN+¡-Ti ¼ primary TiB; ¼ binary eutectic ¢-Ti+TiB ¼ solid transformation from ¢-Ti to ¡-Ti.