Experimental investigations on the effect of rod surface roughness on lubrication characteristics of a hydraulic O-ring seal

2021 ◽  
Vol 156 ◽  
pp. 106791
Author(s):  
Bingqing Wang ◽  
Xiangkai Meng ◽  
Xudong Peng ◽  
Yuan Chen
Keyword(s):  
Surface Roughness ◽  
Experimental Investigations ◽  
Ring Seal ◽  
Lubrication Characteristics

Experimental Investigations of the Machinability of Titanium Alloy TC4 with Different Hydrogen Contents

2011 ◽  
Vol 418-420 ◽  
pp. 1307-1311
Author(s):  
Jun Hu ◽  
Yong Jie Bao ◽  
Hang Gao ◽  
Ke Xin Wang
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Cutting Force ◽  
Hydrogen Content ◽  
Experimental Results ◽  
Cutting Conditions ◽  
Experimental Investigations ◽  
Cutting Condition ◽  
The Given

The experiments were carried out in the paper to investigate the effect of adding hydrogen in titanium alloy TC4 on its machinability. The hydrogen contents selected were 0, 0.25%, 0.49%, 0.63%, 0.89% and 1.32%, respectively. Experiments with varing hydrogen contents and cutting conditions concurrently. Experimental results showed that the cutting force of the titanium alloy can be obviously reduced and the surface roughness can be improved by adding appropriate hydrogen in the material. In the given cutting condition, the titanium alloy TC4 with 0.49% hydrogen content showed better machinability.

Experimental investigations into abrasive flow machining (AFM) of 3D printed ABS and PLA parts

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nitin Dixit ◽  
Varun Sharma ◽  
Pradeep Kumar
Keyword(s):  
Surface Roughness ◽  
Biomedical Applications ◽  
Fused Deposition Modeling ◽  
Experimental Investigations ◽  
Future Research ◽  
Content Type ◽  
Abrasive Flow Machining ◽  
Fused Deposition ◽  
Cylindrical Parts ◽  
3D Printed

Purpose The surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM). Design/methodology/approach A hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa). Findings The developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts. Practical implications The FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study. Research limitations/implications The present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques. Originality/value An abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.

EXPERIMENTAL INVESTIGATIONS INTO THE INFLUENCING PARAMETERS OF ELECTROCHEMICAL MACHINING OF AISI 202

2008 ◽  
Vol 07 (02) ◽  
pp. 337-343 ◽  
Author(s):  
T. SEKAR ◽  
R. MARAPPAN
Keyword(s):  
Surface Roughness ◽  
Metal Removal ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
High Energy ◽  
Experimental Investigations ◽  
Metal Removal Rate ◽  
Hard Materials ◽  
Influencing Parameters ◽  
Traditional Process

Electrochemical machining (ECM) is a non-traditional process used mainly to cut hard or difficult to cut metals, where the application of a more traditional process is not convenient. Those difficult to cut metals demand high energy to form chips, which can result in thermal effects due to the high temperatures inherent to the process in the chip–tool interface. In traditional processes, the heat generated during the cut is dissipated to the tool, chip, workpiece and environment, affecting the surface integrity of the workpiece, mainly for those hard materials. In this work, experimental investigations have been made on the various influencing parameters involved in the Metal removal rate (MRR) and Surface roughness using ECM on AISI 202 steel. The major intervening parameters are studied and the relationship between the parameters has been determined to achieve maximum metal removal rate and minimum surface roughness by using NaNO 3-Aqua solution.

Theoretical Approach to Turbulent Lubrication Problems Including Surface Roughness Effects

1989 ◽  
Vol 111 (1) ◽  
pp. 17-22 ◽  
Author(s):  
H. Hashimoto ◽  
S. Wada
Keyword(s):  
Surface Roughness ◽  
Velocity Distribution ◽  
Boundary Layers ◽  
Theoretical Approach ◽  
Turbulent Boundary Layers ◽  
Distribution Law ◽  
Roughness Effects ◽  
Relative Roughness ◽  
Lubrication Equation ◽  
Lubrication Characteristics

A new theoretical approach to turbulent lubrication problems including the surface roughness effects is described. On the basis of a logarithmic velocity distribution law in the turbulent boundary layers, the resistance laws for pressure and shear flows in the lubricant film are formulated separately in both cases of smooth and homogeneous rough surfaces. Moreover, combining the bulk flow concept proposed by Hirs with the formulated resistance laws, the generalized turbulent lubrication equation including the surface roughness effects is derived. Some numerical results for the modified turbulence coefficients are presented in the graphic form for different values of relative roughness, and the effects of surface roughness on the turbulent lubrication characteristics are generally discussed.

Experimental Evaluation of a Mixed Friction Hydrostatic Mechanical Face Seal Model Considering Radial Taper, Thermal Taper, and Wear

1982 ◽  
Vol 104 (4) ◽  
pp. 439-447 ◽  
Author(s):  
L. A. Young ◽  
A. O. Lebeck
Keyword(s):  
Surface Roughness ◽  
Radial Profile ◽  
Surface Characteristics ◽  
Experimental Investigations ◽  
Test Duration ◽  
Face Seal ◽  
Mixed Friction ◽  
Face Seals ◽  
Water Test ◽  
Mechanical Face Seal

In this paper the results of experimental investigations of the effects of radial taper on mechanical face seals are presented and compared to theory. The previously published theory considers the effects of thermal taper caused by a temperature gradient in the seal rings; mixed friction in the case where load support is shared between hydrostatic support and partial contact of the seal faces; surface roughness, which affects both load sharing and leakage; and wear, which alters the radial profile. Fifteen tests were run using a 100 mm diameter carbon versus tungsten carbide seal at 1800 rpm and 3.45 MPa in water. Test duration was up to 100 hr. Varying amounts of radial taper were used. Tests were run at balance ratios of 1.00 and 0.75. Initial and final surface profiles were recorded. Seal torque, leakage, and face temperatures were recorded as functions of time. Results show that theory predicts initial torque and leakage as functions of initial taper quite well, given knowledge of seal surface characteristics. Predicted equilibrium thermal taper as a function of torque for a balance ratio of 1.0 is good. For a seal having a balance ratio of 0.75, predicted equilibrium thermal rotation shows some agreement but more experimental data are needed. The results of 1.00 balance ratio tests suggest that after a long period of operation, any initial taper will be worn away and the seal would continue to operate as a parallel face seal. Results from long-term tests indicate that the wear coefficient is not a constant. While the experimental results support the basic concepts of the model, the results show where further work must be done to better understand the role of surface roughness and wear processes in mechanical face seals.

Research on the Surface Roughness Parameters of Micro-EDM

2013 ◽  
Vol 572 ◽  
pp. 281-286 ◽  
Author(s):  
Zhi Jie Chen ◽  
Ji Hong Shen ◽  
Yun Tao Dai
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Surface Topography ◽  
Evaluation Method ◽  
Micro Edm ◽  
Roughness Parameters ◽  
Surface Roughness Parameters ◽  
Evaluation Problem ◽  
Lubrication Characteristics ◽  
Morphology Characteristics

The surface topography errors of micro-EDM are mainly composed of surface roughness, surface waveness and so on. Research shows that the surface morphology provides a lot of useful information, which has serious influence on the friction and lubrication characteristics of the surface. However, for the micro-EDM surface topography evaluation problem, researchers have been using surface roughness parameters and evaluation method of mechanical process, which restrict the micro-EDM technology further development. On this account, the surface roughness parameters of micro-EDM have been deeply studied in this paper according to its technology characteristics and the surface morphology characteristics, therefore, the main researches and creative points are obtained, which the influence that the surface roughness of micro-EDM parts impact on their using performance is analyzed, and based on the surface morphology characteristics, some roughness evaluation parameters are given respectively according to peaks and valley, moreover, their numerical calculation are also gained.

Experimental investigations of nanosecond-pulsed Nd:YAG laser beam micromachining on 304 stainless steel

2018 ◽  
Vol 1 (1) ◽  
pp. 62-75 ◽  
Author(s):  
Rasmi Ranjan Behera ◽  
Mamilla Ravi Sankar ◽  
Prahlad Kumar Baruah ◽  
Ashwini Kumar Sharma ◽  
Alika Khare
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Laser Beam ◽  
Nd:Yag Laser ◽  
Research Work ◽  
Scanning Speed ◽  
304 Stainless Steel ◽  
Experimental Investigations ◽  
Micro Channel ◽  
Micro Channels

The demand for miniaturized components is increasing day by day as their application varies from industry to industry such as biomedical, micro-electro-mechanical system and aerospace. In the present research work, high-quality micro-channels are fabricated on 304 stainless steel by laser beam micromachining process with nanosecond Nd:YAG laser. The laser pulse energy (LPE), scanning speed (SS) and scanning pass number (SP No.) are used as the process parameters, whereas the depth and width of the kerf as well as the surface roughness are used to characterize the micro-channels. It is found that the kerf depth, width and surface roughness decrease with increase in the SS. The kerf depth sharply increases with increase in the SP No. The kerf width is minimum at 30 mJ LPE, 400 µm s‒1 SS and 10 SP No. The minimum surface roughness is observed at 30 mJ LPE, 500 µm s‒1 SS and 10 SP No. The oxygen content is found to gradually decrease with the distance from the centre of the micro-channel. Based on the experimental results, optimized input parameters can be offered to control the micro-channel dimensions and improve their surface finish effectively on stainless steel.

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