Microstructures and Properties of Ni25 and Fe304 Repairing Layers Prepared by Plasma Surfacing

2012 ◽  
Vol 466-467 ◽  
pp. 357-360
Author(s):  
Wen Quan Wang ◽  
Bao Sheng Lu ◽  
Chang Long Shan
Keyword(s):  
Cast Iron ◽  
Surface Defects ◽  
Nodular Cast Iron ◽  
Xrd Analysis ◽  
Metal Compounds ◽  
Columnar Grains ◽  
Plasma Surfacing ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Interface Line

Microstructures and properties of plasma surfaced Ni25 and Fe304 layers prepared on nodular cast iron substrate were investigated. The study showed that the interface boundary existed between the layers and substrate. Compared with typical microstructures of welded joint, the similar columnar grains in the layers perpendicular to the interface line were observed, which were hardly seen in the plasma sprayed coating. The conclusion could be drawn that the bonding between the Ni25 and Fe304 layers and nodular cast iron substrate belonged to the metallurgical cohesion. The XRD analysis showed that the metal compounds such as Ni4B3，Cr7BC4，γ-(Fe, Ni) and Cr7C3were found in the layers. The study demonstrated that the layers had proper strength and hardness to repair the surface defects of the nodular cast iron.

Microstructures and Properties of Plasma Surfaced NiCrBSi+WC/Co Layers

2011 ◽  
Vol 291-294 ◽  
pp. 109-112
Author(s):  
Wen Quan Wang ◽  
Bao Sheng Lu ◽  
Shi Ming Huang ◽  
Qun You
Keyword(s):  
Welded Joint ◽  
Xrd Analysis ◽  
Interface Boundary ◽  
Die Steel ◽  
Columnar Grains ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Interface Line

Microstructures and properties of plasma surfaced NiCrBSi+20%WC/12Co layer prepared on the die steel (H13) substrate were investigated. The study showed that the interface boundary existed between the layer and substrate. Compared with the typical microstructures of welded joint, the similar columnar grains in the layer perpendicular to the interface line were observed, which were never seen in the plasma sprayed coating. The conclusion could be drawn that the bonding between the NiCrBSi+20%WC/12Co layer and H13 substrate belonged to the metallurgical cohesion. The XRD analysis showed that the main phases in the layer included γ-(Fe, Ni), Cr7BC4, Ni4B3, Cr7C3 and Co7W6, which brought higher strength and higher hardness to the surfaced layer than the H13 substrate.

scholarly journals Effect of Vacuum Annealing on the Nickel-Based Coatings Deposited on a CGI Cast Iron through Atmospheric Plasma Spraying

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 963
Author(s):  
Peihu Gao ◽  
Baiyang Chen ◽  
Shencong Zeng ◽  
Zhong Yang ◽  
Yongchun Guo ◽  
...  
Keyword(s):  
Cast Iron ◽  
Adhesion Strength ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Atmospheric Plasma ◽  
Compacted Graphite ◽  
Graphite Cast Iron ◽  
Nickel Based Alloy ◽  
Sprayed Coating ◽  
Plasma Sprayed

Plasma-sprayed nickel-based self-fusion alloy coatings were annealed in a vacuum at 990, 1020 and 1050 °C for 20 min to increase the bonding between the compacted graphite cast iron substrate and coating, as well as the inner cohesion of the coatings. It was found that nickel and chromium diffused between nickel-based alloy coatings and compacted graphite cast iron substrate. A metallurgical translation zone with a thickness up to 1145 μm formed during the vacuum annealing, which resulted in an enhancement of the adhesion between the coating and substrate. The adhesion strength at room temperature was increased from the as-sprayed coating of 33.4 MPa to the annealed one of 163 MPa. Meanwhile, the adhesion strength at 500 °C reached 146 MPa. Conversely, the inner cohesion of the coating was improved with the particles’ interfaces healed after vacuum annealing. The micro-hardness of the annealed coatings was increased to 902 HV from the as-sprayed one of 578 HV.

Evaluation of microstructure and electrochemical behavior of dual-layer NiCrAlY/mullite plasma sprayed coating on high silicon cast iron alloy

2017 ◽  
Vol 43 (16) ◽  
pp. 14146-14155 ◽  
Author(s):  
Alireza Jam ◽  
Seyed Mohammad Reza Derakhshandeh ◽  
Hosein Rajaei ◽  
Amir Hossein Pakseresht
Keyword(s):  
Cast Iron ◽  
Electrochemical Behavior ◽  
Iron Alloy ◽  
High Silicon ◽  
Sprayed Coating ◽  
Plasma Sprayed

Comparative study of conventional and microwave heating of polyacrylonitrile-based fibres

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guozhen Zhao ◽  
Jianhua Liu ◽  
Lei Xu ◽  
Shenghui Guo
Keyword(s):  
Microwave Heating ◽  
Surface Defects ◽  
Energy Dispersive Spectrometer ◽  
Xrd Analysis ◽  
Economic Benefits ◽  
Heating Time ◽  
Oxidation Temperature ◽  
Conventional Heating ◽  
Heating Method ◽  
Molecular Arrangement

Abstract The effects of the conventional heating method and the microwave heating method on polyacrylonitrile-based fibres in the temperature range of 180–280 °C were investigated. Fourier transform infrared spectroscopy, X-ray wide-angle scattering, Raman spectroscopy, energy-dispersive spectrometer, scanning electron microscopy and bulk density were used to characterise the properties of the samples. Results show that the microwave heating method can shorten the pre-oxidation time, reduce pre-oxidation temperature and reduce the number of surface defects. The pre-oxidised fibres obtained by the microwave heating method exhibit not only good crystallite size but also a smooth surface. Atomic morphology and molecular arrangement are orderly inside the fibre. The FT-IR spectrum shows that the oxidation reaction occurs at 220 °C, and the CI value of PAN fibers stabilised by microwave heating is the larger than the fibers stabilised by conventional heating. XRD analysis shows that fibers stabilised by microwave heating have low stack domains. The SEM and Raman spectra indicate that hydrogen peroxide can improve the surface finish of the fibers and reduce defects. Microwave heating can reduce the pre-oxidation temperature by about 20 °C and shorten the heating time. The economic benefits of using this method are significantly improved.

Effective properties of nodular cast-iron: A multi-scale computational approach

2014 ◽  
Vol 82 ◽  
pp. 378-390 ◽  
Author(s):  
F.D. Carazo ◽  
S.M. Giusti ◽  
A.D. Boccardo ◽  
L.A. Godoy
Keyword(s):  
Cast Iron ◽  
Effective Properties ◽  
Nodular Cast Iron ◽  
Computational Approach ◽  
Multi Scale
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