Preliminary Results on Finishing of WC-Co Coating by Magnetorheological Finishing Process

2019 ◽  
Author(s):  
Gourhari Ghosh ◽  
Ajay Sidpara ◽  
P. P. Bandyopadhyay
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Magnetorheological Finishing ◽  
Machining Time ◽  
Mr Fluid ◽  
Mechanical Abrasion ◽  
Deformed Layer ◽  
End Use

Abstract Thermal spray coating has the ability to enhance the lifetime of engineering components by reinforcing the surface properties. The surface roughness of the as-sprayed coatings needs to be suitably finished for its end use. The nanofinished WC-Co coatings are widely used in aerospace and automobile industries. In this present investigation, surface grinding followed by the magnetorheological finishing (MRF) processes is employed for finishing of WC-Co coating. Boron carbide (B4C) powder is used as the abrasive particles in the MRF process. MRF spot finishing technique is performed on the ground coating. The plastically deformed layer from the ground surface is removed completely by the gentle mechanical abrasion of MR fluid ribbon. The surface roughness and volume of material removed are measured over the finishing time. It is perceived that the surface roughness of the finishing spot is increased after a threshold machining time. This is attributed to the aging of MR fluid and the mechanical abrasion of wear debris. The experiment is also performed with the assistance of Murakami’s reagent to perform etching and finishing, simultaneously. A comparatively higher finishing rate is observed in this case.

scholarly journals PELAPISAN PERMUKAAN DALAM NOSEL ROKET RKX100 DENGAN Cr2C3-NiCr HVOF: OPTIMASI KEKUATAN LEKAT MELALUI VARIASI KEKASARAN PERMUKAAN

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondan T.Sofyan ◽  
Yus Prasetyo ◽  
Sayid Ardiansyah ◽  
Yus Prasetyo ◽  
Edy Sofyan
Keyword(s):  
Surface Roughness ◽  
Thermal Spray ◽  
Bonding Strength ◽  
Spray Coating ◽  
Hardness Measurement ◽  
Thermal Spray Coating ◽  
Optical Microscope ◽  
Mechanical Interlocking ◽  
Micro Hardness ◽  
Scanning Electron

Nozzle of RKX100 rocket contributes 30 percent to the total weight of the structure, so that allowing further research on weight reduction. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. A series of study on the characteristics of various type of HVOF coating material have been being conducted. This paper presented the investigation on the HVOF Cr2C3-NiCr thermal spray coating, in particular, the optimization of bonding strength by varying surface roughness of substrates. Characterization included bonding strength test, micro hardness measurement and micro structural observation with optical microscope and scanning electron micriscope (SEM). The results showed that grit blasting pressure increass the surface roughness from 4,54 um to 5.72 um at the pressure of 6 bar. Average micro hardness of the coating was 631 VHN 300. Coating applied to the surface with rougness of 5.42 um possessed the highest bonding strength, 44 MPa. Microstructural observation by using optical microscope and scanning electron microscope (SEM) confirmed dense lamellae structure with variable composition. High coating adherence was found to be due to mechanical interlocking.

Experimental Research of Cluster Magnetorheological Finishing on Anodic Oxide Film of Aluminum

2016 ◽  
Vol 874 ◽  
pp. 158-166
Author(s):  
Run Chen ◽  
Jia Bin Lu ◽  
Qiu Sheng Yan ◽  
Xiao Lan Xiao ◽  
De Yuan Li
Keyword(s):  
Surface Roughness ◽  
Oxide Film ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Magnetorheological Finishing ◽  
Machining Time ◽  
Good Surface

The polishing experiments of anodic oxide film of aluminum were performed to research the influence of polishing parameters on the surface roughness and material removal rate in the cluster magnetorheological finishing (MRF). Experimental results demonstrate that a mirror effect can be reached when the anodic oxide film of aluminum is polished by the Cluster MRF. The roughness of the workpiece surface after polishing for 15 min is decreased from Ra 0.575μm to Ra 4.13nm and the material removal rate is 0.653mg/min. With the extension of the polishing time, the surface roughness rapidly declines at first and then slowly decreases. When the machining time is more than 15min, the anodic oxide film of aluminum is easily worn out, resulting in a sharp increase in the surface roughness. The machining gap between the workpiece and the polishing plate influences the polishing effect of anodic oxide film of aluminum. With the increase of the machining gap, the material removal rate decreases and the surface roughness increases. A good surface quality can be got at the machining gap of 1.1mm. The type and size of abrasive particles will directly affect the polishing effect of anodic oxide film of aluminum, and when using CeO2 abrasive with the particle size of W3, a higher material removal rate and a smaller surface roughness can be obtained.

Impurity Effects on Shear Adhesive Strength of Tungsten Carbide Thermal Spray Coatings on Steel

2001 ◽  
Vol 7 (S2) ◽  
pp. 328-329
Author(s):  
Seetala V. Naidu ◽  
James D. Garber ◽  
Gary A. Glassc
Keyword(s):  
Surface Roughness ◽  
Tungsten Carbide ◽  
Thermal Spray ◽  
Adhesive Strength ◽  
Steel Substrate ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Test Method ◽  
Coating Process ◽  
Ring Shear

We have used High Velocity Oxy-Fuel (HVOF) thermal spray coating process to obtain tungsten carbide coatings on steel. It is important to control the powder quality and surface roughness of the substrate in the thermal spray coating process to obtain good adherence. The adhesive strength is greatly effected by the interfacial impurities. Most commonly used in the thermal spray industry is Al2O3 grit abrasive for good surface roughness of steel substrate to produce anchor patterns for the coating. The previous studies indicated that some fine Al2O3 particles are trapped in the rough surface grooves during this process. The ring shear test method, described previously, appears to give the most accurate results on shear adhesive strength. The ring shear strength test was comprised of a 0.02” thick and 0.25” wide ring coating on a 1” diameter cylindrical substrate rod. This rod is placed in a disk with a cylindrical hole of the rod size and an incremental pressure is applied on the rod.

Toward Magnetorheological Finishing of Magnetic Materials

2007 ◽  
Vol 129 (5) ◽  
pp. 961-964 ◽  
Author(s):  
Shai N. Shafrir ◽  
John C. Lambropoulos ◽  
Stephen D. Jacobs
Keyword(s):  
Magnetic Material ◽  
Surface Roughness ◽  
Magnetic Materials ◽  
Material Removal ◽  
Subsurface Damage ◽  
Magnetorheological Finishing ◽  
Optical Glasses ◽  
Material Surfaces ◽  
Finishing Process ◽  
Deformed Layer

Magnetorheological finishing (MRF) is a precision optical finishing process traditionally limited to processing only nonmagnetic materials, e.g., optical glasses, ceramics, polymers, and metals. Here we demonstrate that MRF can be used for material removal from magnetic material surfaces. Our approach is to place an MRF spot on machined surfaces of magnetic WC-Co materials. The resulting surface roughness is comparable to that produced on nonmagnetic materials. This spotting technique may be used to evaluate the depth of subsurface damage, or deformed layer, induced by earlier manufacturing steps, such as grinding and lapping.

scholarly journals Using uniform design and regression methodology of turning parameters study of nickel alloy

2021 ◽  
Author(s):  
Shao-Hsien Chen ◽  
Chih-Hung Hsu
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Nickel Alloy ◽  
Design Methodology ◽  
Cutting Tool ◽  
Uniform Design ◽  
Machining Time ◽  
Variable Parameters ◽  
Cutting Test ◽  
Set Up

AbstractThe nickel alloy has good mechanical strength and corrosion resistance at high temperature; it is extensively used in aerospace and biomedical and energy industries, as well as alloy designs of different chemical compositions to achieve different mechanical properties. However, for high mechanical strength, low thermal conductivity, and surface hardening property, the nickel alloy has worse cutting tool life and machining efficiency than general materials. Therefore, how to select the optimum machining parameters will influence the workpiece quality, cost, and machining time. This research will be using a new experimental design methodology to the cutting parameter planning for nickel-based alloy cutting test, and used the uniform design methodology to cutting test to reduce the number of experiments. Three independent variable parameters are set up, including cutting speed, feed rate, and cutting depth, and four dependent variable parameters are set up, including cutting tool wear, surface roughness, machining time, and cutting force. A nickel alloy turning parameter model is built by using regression analysis to further predict the I/O relationship among various combinations of variables. The errors between actual values and prediction values are validated. When the cutting tool wear (VB) is 2.72~6.18%, the surface roughness (Ra) is 4.10~7.72%, the machining time (T) is 3.75~8.82%, and the cutting force (N) is 1.54~7.42%; the errors of various dependent variables are approximately less than 10%, so a high precision estimation model is obtained through a few experiments of uniform design method.

Experimental investigation into polishing of monocrystalline silicon wafer using double-disc chemical assisted magnetorheological finishing process

2021 ◽  
pp. 095440622098384
Author(s):  
Mayank Srivastava ◽  
Pulak M Pandey
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Flow Rate ◽  
Silicon Wafers ◽  
Monocrystalline Silicon ◽  
Slurry Flow ◽  
Magnetorheological Finishing ◽  
Finishing Process ◽  
Process Factors ◽  
Slurry Flow Rate

In the present work, a novel hybrid finishing process that combines the two preferred methods in industries, namely, chemical-mechanical polishing (CMP) and magneto-rheological finishing (MRF), has been used to polish monocrystalline silicon wafers. The experiments were carried out on an indigenously developed double-disc chemical assisted magnetorheological finishing (DDCAMRF) experimental setup. The central composite design (CCD) was used to plan the experiments in order to estimate the effect of various process factors, namely polishing speed, slurry flow rate, percentage CIP concentration, and working gap on the surface roughness ([Formula: see text]) by DDCAMRF process. The analysis of variance was carried out to determine and analyze the contribution of significant factors affecting the surface roughness of polished silicon wafer. The statistical investigation revealed that percentage CIP concentration with a contribution of 30.6% has the maximum influence on the process performance followed by working gap (21.4%), slurry flow rate (14.4%), and polishing speed (1.65%). The surface roughness of polished silicon wafers was measured by the 3 D optical profilometer. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were carried out to understand the surface morphology of polished silicon wafer. It was found that the surface roughness of silicon wafer improved with the increase in polishing speed and slurry flow rate, whereas it was deteriorated with the increase in percentage CIP concentration and working gap.

scholarly journals SURFACE ROUGHNESS CONSIDERATIONS IN DESIGN FOR ADDITIVE MANUFACTURING - A LITERATURE REVIEW

2021 ◽  
Vol 1 ◽  
pp. 2841-2850
Author(s):  
Didunoluwa Obilanade ◽  
Christo Dordlofva ◽  
Peter Törlind
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Literature Review ◽  
Future Research ◽  
Reduction Potentials ◽  
Research Fields ◽  
Post Process ◽  
Accessibility Issues ◽  
End Use ◽  
And Performance

AbstractOne often-cited benefit of using metal additive manufacturing (AM) is the possibility to design and produce complex geometries that suit the required function and performance of end-use parts. In this context, laser powder bed fusion (LPBF) is one suitable AM process. Due to accessibility issues and cost-reduction potentials, such ‘complex’ LPBF parts should utilise net-shape manufacturing with minimal use of post-process machining. The inherent surface roughness of LPBF could, however, impede part performance, especially from a structural perspective and in particular regarding fatigue. Engineers must therefore understand the influence of surface roughness on part performance and how to consider it during design. This paper presents a systematic literature review of research related to LPBF surface roughness. In general, research focuses on the relationship between surface roughness and LPBF build parameters, material properties, or post-processing. Research on design support on how to consider surface roughness during design for AM is however scarce. Future research on such supports is therefore important given the effects of surface roughness highlighted in other research fields.

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