Characteristics of Cobalt Chromium Alloy Surfaces Finished Using Magnetic Abrasive Finishing

2012 ◽  
Author(s):  
Arthur A. Graziano ◽  
Vasishta Ganguly ◽  
J. Whittaker Bullard ◽  
Hitomi Yamaguchi ◽  
Tony Schmitz
Keyword(s):  
Contact Angle ◽  
The Other ◽  
Surface Pattern ◽  
Initial Surface ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Surface Patterns

Freeform surfaces, including the femoral components of knee prosthetics, present a significant challenge in manufacturing. The finishing process is often performed manually, leading to high variation in quality. This study proposes using Magnetic Abrasive Finishing (MAF) to finish the cobalt chromium (Co-Cr) alloy femoral components of knee prosthetics and varying the surface pattern to alter surface wettability, which influences the tribological properties of the surfaces. As a first step, flat workpieces of the same material were used in this paper. To obtain an understanding of the relationship between surface pattern and wettability, two sets of finishing conditions were developed to yield two different surface patterns while maintaining roughness values (2–5 nm Ra). One surface consists of long cutting marks exhibiting strong directionality, while the other consists of short, intermittent cutting marks. The surface with strong directionality resulted in an increased contact angle between the workpiece and de-ionized water (from 90.0°±1.5° to 93.8°±2.5°), thus a decrease in wettability. The other surface showed a decreased contact angle (from 98.7°±5.3° to 93.3°±3.7°), thus an increase in wettability. This study experimentally demonstrates the feasibility of MAF to alter surface pattern—and to potentially alter the wettability—while maintaining initial surface roughness at a nanometer scale.

Control of Lay on Cobalt Chromium Alloy Finished Surfaces Using Magnetic Abrasive Finishing and Its Effect on Wettability

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Arthur A. Graziano ◽  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Hitomi Yamaguchi
Keyword(s):  
Surface Roughness ◽  
Deionized Water ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Magnetic Abrasive Finishing ◽  
Wetting Properties ◽  
Chromium Alloys ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Intermittent Cutting

Freeform surfaces, including the femoral components of knee prosthetics, present a significant challenge in manufacturing. The finishing process is often performed manually, which leads to surface finish variations. In the case of knee prosthetics, this can be a factor leading to accelerated wear of the polyethylene tibial component. The wear resistance of polyethylene components might be influenced by not only the roughness but also the lay of femoral component surfaces. This study applies magnetic abrasive finishing (MAF) for nanometer-scale finishing of cobalt chromium alloys, which are commonly used in knee prosthetics and other freeform components. Using flat disks as workpieces, this paper shows the dominant parameters for controlling the lay in MAF and demonstrates the feasibility of MAF to alter the lay while controlling the surface roughness. The manually finished disk surfaces (with roughness around 3 nm Sa), consisting of random cutting marks, were compared to MAF-produced surfaces (also with roughness around 3 nm Sa) with different lays. Tests using deionized water droplets show that the lay influences the wetting properties even if the surface roughness changes by no more than a nanometer. Surfaces with unidirectional cutting marks exhibit the least wettability, and increasing the cross-hatch angle in the MAF-produced surfaces increases the wettability. Surfaces consisting of short, intermittent cutting marks were the most wettable by deionized water.

Uniform Internal Finishing of SUS304 Stainless Steel Bent Tube Using a Magnetic Abrasive Finishing Process

2004 ◽  
Vol 127 (3) ◽  
pp. 605-611 ◽  
Author(s):  
Hitomi Yamaguchi ◽  
Takeo Shinmura ◽  
Megumi Sekine
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Removal Rate ◽  
Surface Finishing ◽  
Initial Surface ◽  
Magnetic Abrasive Finishing ◽  
Sus304 Stainless Steel ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
The Magnetic Field

This research studies the factors affecting the conditions required for successful uniform internal finishing of SUS304 stainless steel bent tube by a Magnetic abrasive finishing process. In particular, the effects of the magnetic field and ferrous particles were investigated. Local intensification of the magnetic field is accomplished by offsetting the axis of pole rotation from elbow axis. This effect enables local control of the material removal rate, which leads to uniformity in the finished surface regardless of the initial surface conditions. A two-phase finishing process controlling the size of the ferrous particles is proposed to achieve efficient fine surface finishing.

Improve the Micro-hardness of Single Point Incremental Forming Product Using Magnetic Abrasive Finishing

2020 ◽  
Vol 38 (8A) ◽  
pp. 1137-1142
Author(s):  
Baqer A. Ahmed ◽  
Saad K. Shather ◽  
Wisam K. Hamdan
Keyword(s):  
Vickers Hardness ◽  
Feed Rate ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Step Size ◽  
Coil Current ◽  
Magnetic Abrasive Finishing ◽  
Finishing Process ◽  
Abrasive Finishing

In this paper the Magnetic Abrasive Finishing (MAF) was utilized after Single Point Incremental Forming (SPIF) process as a combined finishing process. Firstly, the Single Point Incremental forming was form the truncated cone made from low carbon steel (1008-AISI) based on Z-level tool path then the magnetic abrasive finishing process was applied on the surface of the formed product. Box-Behnken design of experiment in Minitab 17 software was used in this study. The influences of different parameters (feed rate, machining step size, coil current and spindle speed) on change in Micro-Vickers hardness were studied. The maximum and minimum change in Micro-Vickers hardness that achieved from all the experiments were (40.4 and 1.1) respectively. The contribution percent of (feed rate, machining step size, coil current and spindle speed) were (7.1, 18.068, 17.376 and 37.894) % respectively. After MAF process all the micro surface cracks that generated on the workpiece surface was completely removed from the surface.

scholarly journals Development of a New Finishing Process Combining a Fixed Abrasive Polishing with Magnetic Abrasive Finishing Process

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 81
Author(s):  
Yanhua Zou ◽  
Ryunosuke Satou ◽  
Ozora Yamazaki ◽  
Huijun Xie
Keyword(s):  
Alumina Ceramic ◽  
Ceramic Plate ◽  
Polishing Process ◽  
High Quality ◽  
Influence Of Process Parameters ◽  
Magnetic Abrasive Finishing ◽  
Nano Scale ◽  
Finishing Process ◽  
Abrasive Finishing ◽  
Fixed Abrasive

High quality, highly efficient finishing processes are required for finishing difficult-to-machine materials. Magnetic abrasive finishing (MAF) process is a finishing method that can obtain a high accuracy surface using fine magnetic particles and abrasive particles, but has poor finishing efficiency. On the contrary, fixed abrasive polishing (FAP) is a polishing process can obtain high material removal efficiency but often cannot provide a high-quality surface at the nano-scale. Therefore, this work proposes a new finishing process, which combines the magnetic abrasive finishing process and the fixed abrasive polishing process (MAF-FAP). To verify the proposed methodology, a finishing device was developed and finishing experiments on alumina ceramic plates were performed. Furthermore, the mechanism of the MAF-FAP process was investigated. In addition, the influence of process parameters on finishing characteristics is discussed. According to the experimental results, this process can achieve high-efficiency finishing of brittle hard materials (alumina ceramics) and can obtain nano-scale surfaces. The surface roughness of the alumina ceramic plate is improved from 202.11 nm Ra to 3.67 nm Ra within 30 min.

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