Influence of Nitrocarburizing Process Parameters on the Development of Surface Roughness and Layer Formation

2016 ◽  
Vol 674 ◽  
pp. 325-330 ◽  
Author(s):  
Ewald Badisch ◽  
Andreas Trausmuth ◽  
Manel Rodríguez Ripoll ◽  
Alexander Diem ◽  
Wolfgang Kunze ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Layer Structure ◽  
Compound Layer ◽  
Processing Parameters ◽  
Salt Bath ◽  
Layer Formation ◽  
Depth Profiles ◽  
Original Surface ◽  
Modification Procedure ◽  
Hardness Depth

Nitriding of tools and engineering components is a well-established surface modification procedure in many industries to ensure operational efficiency. The focus of this work is laid on understanding the influence of nitriding processing technology on the resulting surface properties which strongly dominate its tribological performance. Therefore, nitriding layers based on salt bath and plasma procedure were realised using 31CrMoV9 substrate. The surface roughness before nitriding was set to a Ra value of ~0.16 μm which corresponds to at technically fine grinded surface. 3D measurements as well as SEM micrographs of the nitrided surfaces were compared to the original surface prior to the nitriding procedure. Additionally, cross-section microscopy and hardness depth profiles were done to describe nitriding layer structure and nitriding hardness depth (NHD). Results show a correlation of nitriding processing parameters with the resulting compound layer formation and nitriding hardening depth (NHD). An increase of surface roughness during nitriding can be correlated with the growth of ɛ-nitrides on top of the surface.

Pulsed Laser Micro Polishing: An Analytical Method for Predicting Surface Finish

2011 ◽  
Author(s):  
Madhu Vadali ◽  
Chao Ma ◽  
Neil A. Duffie ◽  
Xiaochun Li ◽  
Frank E. Pfefferkorn
Keyword(s):  
Surface Roughness ◽  
Spatial Frequency ◽  
Critical Frequency ◽  
Pulsed Laser ◽  
Processing Parameters ◽  
Capillary Waves ◽  
Initial Surface ◽  
Stainless Steel 316L ◽  
Average Surface ◽  
Original Surface

This project is focused on developing physics based models to predict the outcome of pulsed laser micro polishing (PLμP). Perry et al. [1–3] have modeled PLμP as oscillations of capillary waves with damping resulting from the forces of surface tension and viscosity. They have proposed a critical spatial frequency, fcr, above which a significant reduction in the amplitude of the spatial Fourier components is expected. The current work extends the concept of critical spatial frequency to the prediction of the spatial frequency content and average surface roughness after polishing, given the features of the original surface, the material properties, and laser parameters used for PLμP. The proposed prediction methodology was tested using PLμP results for Nickel, Ti6Al4V, and stainless steel 316L with initial average surface roughnesses from 70 nm to 190 nm. The predicted average surface roughnesses were within 10% to 15% of the values measured on the polished surfaces. The results show that the critical frequency continues to be a useful predictor of polishing results in the spatial frequency domain. The laser processing parameters, as represented by the critical frequency and the initial surface texture therefore can be used to predict the final surface roughness before actually implementing PLμP.

scholarly journals EFFECT OF SALT BATH NITRIDING ON SURFACE ROUGHNESS BEHAVIOUR OF AISI 4140 STEEL

2017 ◽  
Vol 23 (1) ◽  
pp. 45
Author(s):  
Ghelloudj Elhadj ◽  
Mohamed Tahar Hannachi ◽  
Hamid Djebaili
Keyword(s):  
Surface Roughness ◽  
Surface Characterization ◽  
Compound Layer ◽  
Salt Bath ◽  
Initial Surface ◽  
Aisi 4140 Steel ◽  
Aisi 4140 ◽  
Layer Increase ◽  
Structural Surface ◽  
Salt Bath Nitriding

In the present research, AISI 4140 steel was nitrided in salt bath to study and analyze the behaviour of the surface roughness.  The Structural surface characterization behaviour of the nitrided steel was compared to the behaviour of the same steel which was untreated. The nitriding process was implemented in the salt bath component at ten different times (from 1 h to 10 h) when the temperature was constant at (580ºC). The influence of nitriding treatment  on structural properties of the material was studied by scanning electron microscopy (SEM),  microhardness tester and surface profilometer. It was found that salt bath nitriding was effective in improving the surface properties behaviour of this steel, Experimental results showed that the nitrides ε-Fe2-3(N,C) and γ’-Fe4(N,C) present in the compound layer increase the microhardness (406–502 HV0.3),The initial surface roughness values of nitrided samples were higher than those of unnitrided specimens, It also observed that the Increasing the  nitriding  time  increases the surface roughness parameters (Ra, Rq and Rz).

The behaviour of heavily loaded line contacts with transverse roughness

1999 ◽  
Vol 213 (4) ◽  
pp. 309-320 ◽  
Author(s):  
C. J. Hooke
Keyword(s):  
Surface Roughness ◽  
Full Range ◽  
Numerical Results ◽  
Operating Conditions ◽  
Entrainment Velocity ◽  
Original Surface ◽  
Line Contacts ◽  
Transverse Roughness ◽  
Inlet Length

In heavily loaded, piezoviscous contacts the surface roughness tends to be flattened inside the conjunction by any relative sliding of the surfaces. However, before it is flattened, the roughness affects the inlet to the contact, producing clearance variations there. These variations are then convected through the contact, at the entrainment velocity, producing a clearance distribution that differs from the original surface. The present paper explores this behaviour and establishes how the amplitude of the convected clearance varies with wavelength and operating conditions. It is shown that the primary influence is the ratio of the wavelength to the inlet length of the conjunction. Where this ratio is large, the roughness is smoothed and there is little variation in clearance under the conjunction. Where the ratio is small, significant variations in clearance may occur but the precise amplitude and phasing depend on the ratio of slide to roll velocities and on the value of a piezoviscous parameter, c. The numerical results agree closely with existing solutions but extend these to cover the full range of operating conditions.

Observation in the Surface Roughness of Silicon Wafer during Semi-Fixed Abrasive Machining with Large Grains

2009 ◽  
Vol 69-70 ◽  
pp. 253-257
Author(s):  
Ping Zhao ◽  
Jia Jie Chen ◽  
Fan Yang ◽  
K.F. Tang ◽  
Ju Long Yuan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Silicon Wafer ◽  
Processing Parameters ◽  
Wafer Surface ◽  
Abrasive Machining ◽  
Fixed Abrasive ◽  
Is Failure ◽  
Better Than

Semi-fixed abrasive is a novel abrasive. It has a ‘trap’ effect on the hard large grains that can prevent defect effectively on the surface of the workpiece which is caused by large grains. In this paper, some relevant experiments towards silicon wafers are carried out under the different processing parameters on the semi-fixed abrasive plates, and 180# SiC is used as large grains. The processed workpieces’ surface roughness Rv are measured. The experimental results show that the surface quality of wafer will be worse because of higher load and faster rotating velocity. And it can make a conclusion that the higher proportion of bond of the plate, the weaker of the ‘trap’ effect it has. Furthermore the wet environment is better than dry for the wafer surface in machining. The practice shows that the ‘trap’ effect is failure when the workpiece is machined by abrasive plate which is 4.5wt% proportion of bond in dry lapping.

Experimental Research on Surface Roughness of Ultrasonic Assisted Grinding on 7075 Aluminum Alloy

2021 ◽  
Vol 1047 ◽  
pp. 62-67
Author(s):  
Shen Wang ◽  
Le Tong ◽  
Guang Jun Chen ◽  
Mao Xun Wang ◽  
Bin Dai ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Processing Parameters ◽  
7075 Aluminum Alloy ◽  
Machined Surface ◽  
Ultrasonic Assisted Grinding ◽  
Great Performance ◽  
Ultrasonic Assisted ◽  
Conventional Grinding ◽  
Micro Morphology

7075 aluminum alloy is widely used due to its great performance, especially in aerospace area. In this paper, ultrasonic-assisted grinding technology is used to process 7075 aluminum alloy. The data is obtained through experiments, and the surface roughness and morphology of ultrasonic assisted grinding and conventional grinding under different spindle speeds, feed rates, and amplitudes are analyzed. Research has found that the increase in spindle speed and amplitude will improve the quality of the machined surface and reduce the surface roughness by 82.1% and 36%. However, with the increase of feed rate, the surface quality decreased significantly, and the surface roughness increased by 55.6%. The surface micro-morphology of the machined workpiece is observed, and the effects of different processing parameters on the surface micro-morphology are obtained.

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.

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