scholarly journals Experimental Design and Performance Analysis in Plasma Arc Surface Hardening

2012 ◽  
pp. 57-75
Author(s):  
Mohd Idris Shah Ismail ◽  
Zahari Taha ◽  
Mohd Hamdi Abdul Shukor
Keyword(s):  
Surface Roughness ◽  
Experimental Design ◽  
Surface Hardening ◽  
Processing Parameters ◽  
Plasma Arc ◽  
Signal To Noise ◽  
Scanning Velocity ◽  
Hardening Process ◽  
Arc Current ◽  
And Performance

In this paper, the experimental design by using the Taguchi method was employed to optimize the processing parameters in the plasma arc surface hardening process. The evaluated processing parameters are arc current, scanning velocity and carbon content of steel. In addition, the significant effects of the relation between processing parameters were also investigated. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to investigate the effects of these processing parameters. Through this study, not only the increasing in hardened depth and improvement in surface roughness, but the parameters that significantly affect on the hardening performance were also identified. Experimental results showed the effectiveness of this approach. Dalam kertas kerja ini, reka bentuk ujikaji menggunakan kaedah Taguchi digunakan untuk mengoptimumkan parameter pemprosesan dalam proses arka plasma pengerasan permukaan. Parameter pemprosesan yang dinilai adalah arus arka, halaju imbasan dan kandungan karbon dalam keluli. Sebagai tambahan, kesan-kesan penting yang lain seperti hubungan di antara parameter pemprosesan juga diselidiki. Tatasusunan ortogon, nisbah signal to noise (S/N) dan analisis varians (ANOVA) digunakan untuk mengkaji kesan parameter pemprosesan ini. Melalui kajian ini, bukan sahaja kedalaman pengerasan bertambah dan kekasaran permukaan lebih baik, malah parameter pemprosesan yang nyata sekali menpengaruhi prestasi pengerasan dikenal pasti. Hasil percubaan mengesahkan keberkesanan pendekatan ini.

Understanding surface roughness of additively manufactured nickel superalloy for space applications

2019 ◽  
Vol 26 (3) ◽  
pp. 557-565 ◽  
Author(s):  
Travis Edward Shelton ◽  
Dylan Joseph Stelzer ◽  
Carl R. Hartsfield ◽  
Gregory Richard Cobb ◽  
Ryan P. O'Hara ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Laser Fluence ◽  
Nickel Superalloy ◽  
Processing Parameters ◽  
Surface Topology ◽  
Space Applications ◽  
Content Type ◽  
Scan Speed ◽  
And Performance ◽  
Metal Additive

Purpose For many applications, including space applications, the usability and performance of a component is dependent on the surface topology of the additively manufactured part. The purpose of this paper is to present an investigation into minimizing the residual surface roughness of direct metal laser sintering (DMLS) samples by manipulating the input process parameters. Design/methodology/approach First, the ability to manipulate surface roughness by modifying processing parameters was explored. Next, the surface topography was characterized to quantify roughness. Finally, microthruster nozzles were created both additively and conventionally for flow testing and comparison. Findings Surface roughness of DMLS samples was found to be highly dependent on the laser power and scan speed. Because of unintended partially sintered particles adhering to the surface, a localized laser fluence mechanism was explored. Experimental results show that surface roughness is influenced by the varied parameters but is not a completely fluence driven process; therefore, a relationship between laser fluence and surface roughness can be incorporated but not completely assumed. Originality/value This paper serves as an aid in understanding the importance of surface roughness and the mechanisms associated with DMLS. Rather than exploring a more common global energy density, a localized laser fluence was initiated. Moreover, the methodology and conclusions can be used when optimizing parts via metal additive manufacturing.

Effects of Parameters on Surface Roughness of Metal Parts by Selective Laser Melting

2013 ◽  
Vol 834-836 ◽  
pp. 872-875 ◽  
Author(s):  
Qun Qin ◽  
Guang Xia Chen
Keyword(s):  
Surface Roughness ◽  
Power Density ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Processing Parameters ◽  
Laser Power Density ◽  
Laser Melting ◽  
Scanning Velocity ◽  
Metal Parts ◽  
Overlap Ratio

The primary goal of this research is the effects of laser process parameters on surface roughness of metal parts built by selective laser melting. The main processing parameters used to control the surface roughness of melted layers are laser power, scanning velocity and overlap ratio. In our work, an orthogonal experimental design was employed to find the changing rules of the surface roughness through changing SLM processing parameters. The results show that the overlap ratio is the most important factor to affect the surface roughness. When the overlap ratio is below 50%, the surface roughness value of melted layers will decrease with laser power density increasing. When the overlap ratio is higher than or equal to 50%, the surface roughness value increases with the laser power density increasing. The optimal parameters of laser power 143W, scanning velocity 5m/min and overlap ratio 30% can be used to achieve melted layers with the best surface quality in our experiments, and the roughness value increases with slicing thickness increasing and the surface bias angle decreases.

Influence of Nanosecond Laser Processing Parameters on the Titanium Alloy Surfaces Colorization

2017 ◽  
Vol 744 ◽  
pp. 223-227 ◽  
Author(s):  
Chun Ling Li ◽  
Chang Hou Lu
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Focal Plane ◽  
Laser Processing ◽  
Color Space ◽  
Processing Parameters ◽  
B Value ◽  
Nanosecond Laser ◽  
Scanning Velocity ◽  
The Impact

Laser color marking experiments on titanium alloy substrates were carried out to investigate the impact of selected laser processing parameters on the resulting colors. The CIE L*a*b* color space was used to quantify these colors. The surface roughness of the marked color areas was measured by using a TR200 hand-held surface roughness instrument. The relationships between laser parameters and CIE L*a*b* values and surface roughness of the colors were obtained. Results clearly showed that different colors ranging from blue and gray to yellow were produced. Some colors can be obtained by different sets of parameters, while some colors can only be produced by a specific combination of process parameters due to the existence of different forms of heat input and thermal process. The b* value increased to the maximum which represented yellow then decreased. The surface roughness of color areas decreased with the increase of focal plane offset, scanning velocity, or hatch space.

Repairing Damage on Ground Fused Silica by CO2 Laser Irradiation

2010 ◽  
Vol 126-128 ◽  
pp. 401-406 ◽  
Author(s):  
Peng Yao ◽  
Takuro Abe ◽  
Nobuhito Yoshihara ◽  
Tian Feng Zhou ◽  
Ji Wang Yan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Laser Irradiation ◽  
Processing Parameters ◽  
Fused Silica ◽  
Polished Surface ◽  
Initial Surface ◽  
Scanning Velocity ◽  
Etching Depth ◽  
Grinding Method ◽  
Ductile Mode

Fused silica is an important material for optics of ultraviolet laser transmission. It is difficult to be ground in ductile mode because of a high brittleness. In this paper, ductile mode grinding was achieved by a taper grinding method when the initial surface was a polished surface. However, when the initial surface was an unpolished surface, ductile mode grinding could not be realized because of the existence of surface and subsurface damages. The damages on the ground fused silica surface were repaired by CO2 laser irradiation with optimal laser power and scanning velocity. The optimal parameters were determined by studying the viscosity of fused silica and etching depth of laser irradiated groove. Besides laser processing parameters, surface roughness of laser irradiated surface is also greatly influenced by the initial surface roughness.

Performance of two combine harvester header in soybean crops

2020 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
E. M. Samogim ◽  
T. C. Oliveira ◽  
Z. N. Figueiredo ◽  
J. M. B. Vanini
Keyword(s):  
Experimental Design ◽  
Crop Yield ◽  
Field Performance ◽  
Travel Speed ◽  
The Other ◽  
Combine Data ◽  
Mato Grosso ◽  
Tukey Test ◽  
Combine Harvester ◽  
And Performance

The combine harvest for soybean crops market are currently available two types of combine with header or platform, one of conventional with revolving reel with metal or plastic teeth to cause the cut crop to fall into the auger header and the other called "draper" headers that use a fabric or rubber apron instead of a cross auger, there are few test about performance of this combine header for soybean in Mato Grosso State. The aim of this work was to evaluate the soybean harvesting quantitative losses and performance using two types combine header in four travel speed. The experiment was conducted during soybean crops season 2014/15, the farm Tamboril in the municipality of Pontes e Lacerda, State of Mato Grosso. The was used the experimental design of randomized blocks, evaluating four forward harvesting speeds (4 km h-1, 5 km h-1, 6 km h-1 and 7 km h-1), the natural crops losses were analyzed, loss caused by the combine harvester (combine header, internal mechanisms and total losses) and was also estimated the  field performance of each combine. Data were submitted to analysis of variance by F test and compared of the average by Tukey test at 5% probability. The results show the draper header presents a smaller amount of total loss and in most crop yield when compared with the conventional cross auger.

Theoretical justifi cation for use of combined methods for hardening of surfaces of machine parts in order to control their fretting resistance

2020 ◽  
pp. 339-342
Author(s):  
V.F. Bez’yazychny ◽  
M.V. Timofeev ◽  
R.V. Lyubimov ◽  
E.V. Kiselev
Keyword(s):  
Surface Layer ◽  
Fatigue Limit ◽  
Surface Hardening ◽  
Theoretical Justification ◽  
Hardening Process ◽  
Subsequent Application ◽  
Machine Parts ◽  
Combined Methods

The theoretical justification for the hardening process of the surface layer of machine parts for combined methods of surface hardening with subsequent application of strengthening coatings, as well as reducing or increasing the fatigue limit due to the fretting process is presented.

scholarly journals Context-Based Visual Aids to Support the Situation Awareness of Field Engineers Conducting Windstorm Risk Surveys

2019 ◽  
Vol 63 (1) ◽  
pp. 1898-1902
Author(s):  
Sruthy Agnisarman ◽  
Kapil Chalil Madathil ◽  
Jeffery Bertrand
Keyword(s):  
Experimental Design ◽  
Situation Awareness ◽  
Decision Aids ◽  
Weather Condition ◽  
Extreme Weather ◽  
Visual Aids ◽  
Loss Prevention ◽  
Predictive Display ◽  
Independent Variable ◽  
And Performance

Insurance loss prevention survey, specifically windstorm risk inspection survey is the process of investigating potential damages associated with a building or structure in the event of an extreme weather condition such as a hurricane or tornado. This process is performed by a trained windstorm risk engineer who physically goes to a facility to assess the wind vulnerabilities associated with it. This process is highly subjective, and the accuracy of findings depends on the experience and skillsets of the engineer. Although using sensors and automation enabled systems help engineers gather data, their ability to make sense of this information is vital. Further, their Situation Awareness (SA) can be affected by the use of such systems. Using a between-subjects experimental design, this study explored the use of various context-based visualization strategies to support the SA requirements and performance of windstorm risk engineers. The independent variable included in this study is the type of context-based visualizations used (with 3 levels: no visual aids, checklist based and predictive display based visual aids). We measured SA using SAGAT and performance using a questionnaire. SA and performance were found to be higher for the predictive display and checklist based conditions. The findings from this study will inform the design of context-based decision aids to support the SA of risk engineers.

scholarly journals Deep Learning Approach for Vibration Signals Applications

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3929
Author(s):  
Han-Yun Chen ◽  
Ching-Hung Lee
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Parameters Optimization ◽  
Frequency Spectra ◽  
Vibration Signals ◽  
Bearing Faults ◽  
Time Frequency ◽  
And Performance ◽  
The One ◽  
Short Time

This study discusses convolutional neural networks (CNNs) for vibration signals analysis, including applications in machining surface roughness estimation, bearing faults diagnosis, and tool wear detection. The one-dimensional CNNs (1DCNN) and two-dimensional CNNs (2DCNN) are applied for regression and classification applications using different types of inputs, e.g., raw signals, and time-frequency spectra images by short time Fourier transform. In the application of regression and the estimation of machining surface roughness, the 1DCNN is utilized and the corresponding CNN structure (hyper parameters) optimization is proposed by using uniform experimental design (UED), neural network, multiple regression, and particle swarm optimization. It demonstrates the effectiveness of the proposed approach to obtain a structure with better performance. In applications of classification, bearing faults and tool wear classification are carried out by vibration signals analysis and CNN. Finally, the experimental results are shown to demonstrate the effectiveness and performance of our approach.

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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