Modeling of surface roughness for manufactured thin-walled structure

2018 ◽  
Vol 233 (4) ◽  
pp. 1216-1223 ◽  
Author(s):  
Jixiong Fei ◽  
Bin Lin ◽  
Shuai Yan ◽  
Mei Ding ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Dynamic Deformation ◽  
Low Frequency ◽  
Experimental Results ◽  
Superposition Method ◽  
Milling Force ◽  
Machined Surface ◽  
Thin Walled

Deformation of thin-walled structure during machining will influence the surface quality of the final part. Present article investigates this problem and develops a method to predict the surface roughness of the machined surface. To achieve this, the prerequisite is to obtain the dynamic deformation along the milling path. To calculate it accurately, the workpiece is simplified as thin-walled shell and the milling force is simplified as moving input. An expression of the dynamic deformation of the whole structure, which under the excitation of moving milling force, is derived by solving the vibration equation using modal superposition method. Then, the deformation along the milling path is computed by substituting the path coordinates into the expression. The deformation along the milling path is filtered to remove its low-frequency and mid-frequency signals before it is used to evaluate the surface roughness of the machined surface. At last, several machining cases are implemented to demonstrate the proposed method. The experimental results match well with the predicted results. From the predicted and experimental results, it is founded that the deformation during processing is the main reason leading to the poor surface quality of the flexible machined workpiece.

ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Forces ◽  
End Milling ◽  
Complex Structure ◽  
Machined Surface ◽  
End Mills ◽  
Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

In-Process Laser Re-Melting of Thin Walled Parts to Improve Surface Quality after Laser Metal Deposition

2019 ◽  
Vol 813 ◽  
pp. 191-196
Author(s):  
Francesco Bruzzo ◽  
Guendalina Catalano ◽  
Ali Gökhan Demir ◽  
Barbara Previtali
Keyword(s):  
Surface Roughness ◽  
Energy Density ◽  
Surface Quality ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Average Roughness ◽  
Thin Walls ◽  
Energy Inputs ◽  
Thin Walled

Laser metal deposition (LMD) is an additive manufacturing process highly adaptable to medium to large sized components with bulky structures as well as thin walls. Low surface quality of as-deposited LMD manufactured components with average roughness values (Ra) around 15-20μm is one of the main drawbacks that prevent the use of the part without the implementation of costly and time-consuming post-processes. In this work laser re-melting is applied right after LMD process with the use of the same equipment used for the deposition to treat AISI 316L thin walled parts. The surface quality improvement is assessed through the measurement of both areal surface roughness Sa(0.8mm) QUOTE and waviness Wa QUOTE (0.8mm) parameters. Moreover, roughness power spectrum is used to point out the presence of principal periodical components both in the as-deposited and in the re-melted surfaces. Then, the transfer function is calculated to better understand the effects of laser re-melting on the topography evolution, measuring the changes of individual components contributing to the surface roughness such as the layering technique and the presence of sintered particles. Experiments showed that while low energy density inputs are not capable to properly modify the additive surface topography, excessive energy inputs impose a strong periodical component with wavelength equal to the laser scan spacing and directionality determined by the used strategy. When a proper amount of energy density input is used, laser re-melting is capable to generate smooth isotropic topographies without visible periodical surface structures.

Relationship between Electrical Parameters in Combined EDM and Surface Quality

2010 ◽  
Vol 42 ◽  
pp. 436-439 ◽  
Author(s):  
Xin Long Kang ◽  
Dong Man Yu ◽  
Hui Guo ◽  
Chang Pei Shang
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Experimental Results ◽  
Development Prospect ◽  
Electrical Parameters ◽  
Machined Surface ◽  
Process Characteristics ◽  
The Law

This paper presents a deep analysis for the effects of the principles and Electrical Parameters of ultrasonic vibration aided EDM in gas on the roughness of finish machined surface by briefly describing the principles and process characteristics of EDM and combined ultrasonic discharge machining technology, and qualitatively obtains the law of the effects of electrical parameters on the quality of machined surface from the analysis of experimental results. The comparison among the three EDM methods shows the superiority and development prospect of ultrasonic vibration aided EDM in gas.

Characterization of Topography of Cut Surface Based on Theoretical Roughness Indexes

2011 ◽  
Vol 496 ◽  
pp. 194-199 ◽  
Author(s):  
Csaba Felhő ◽  
János Kundrák
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Tribological Properties ◽  
Significant Influence ◽  
Machined Surface ◽  
Edge Geometry ◽  
Mathematical Relation ◽  
Cut Surface

The microgeometry of cut surfaces is one important characteristic of surface quality, since it has significant influence on the tribological properties of working surfaces. In addition to the ability to plan the economical effectiveness of cutting and the accuracy of workpieces the ability to plan the quality of machined surfaces has also emphasized importance. This is why the predictability of surface roughness in planning of technological processes is more and more important. More and more opportunities presenting themselves and one of these is the estimation of the expected value of roughness of the machined surface on the basis of the theoretical value of roughness. The paper focuses on the introduction of a method to describe a mathematical relation between the theoretical and the measured roughness indexes in cutting with tools having defined edge geometry, thus the planning may be more accurate.

scholarly journals SURFACE QUALITY OF PERUVIAN AMAZON WOODS SUBMITTED FOR PLANNING AND SANDING

FLORESTA ◽  
2019 ◽  
Vol 49 (4) ◽  
pp. 671 ◽  
Author(s):  
Miguel Meléndez Cárdenas ◽  
Claudio Gumane Francisco Juizo ◽  
Neptalí Bustamante Guillén ◽  
Hector Enrique Gonzáles Mora ◽  
Ricardo Jorge Klitzke ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Wood Surface ◽  
Cutting Planes ◽  
Processing Conditions ◽  
Peruvian Amazon ◽  
Machined Surface ◽  
Industrial Processing ◽  
Needle Detection

The present study aimed to evaluate the quality of the machined surface of wood of Peruvian Amazonian species under industrial processing conditions. For this, planks of capirona (Calycophyllum spruceanum), cachimbo (Cariniana domestica) and copaíba (Copaifera paupera) were obtained from which four specimens of each species were removed and selected. The specimens were previously conditioned and subsequently submitted to planing and sanding operations, considering three cutting orientations (tangential, radial and intermediate). Then, the quality of the flattened and sanded surfaces of the studied species was evaluated by measuring the surface roughness (Ra) by means of a digital needle detection roughness meter. The results indicated significant differences in wood surface quality among the species in the three evaluated cutting planes, and the capirona radial plane had better planing and sanding quality. Concomitantly, due to the operations performed, the capirona wood allowed a greater possibility for better finishing, followed by cachimbo and copaíba wood, thus being grouped in the 1st, 2nd, and 3rd surface quality classes, respectively.

scholarly journals Investigation of Surface Quality for Minor Scale Diameter of Biodegradable Magnesium Alloys during the Turning Process Using a Different Tool Nose Radius

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1174
Author(s):  
Sophal Hai ◽  
Hwa-Chul Jung ◽  
Won-Hyun Shim ◽  
Hyung-Gon Shin
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Turning Process ◽  
Nose Radius ◽  
Machined Surface ◽  
Tool Nose Radius

The main objective of the study is to analyze the various cutting parameters to investigate the surface quality of the minor scale diameter of magnesium alloy in the dry turning process using a different tool nose radius (r). The surface roughness (Ra) was gauged, and micro-images produced by scanning electron microscopy (SEM) were reviewed to evaluate the machined surface topography. The analysis of variance (ANOVA), linear regression model and signal-to-noise (S/N) ratio were applied to investigate and optimize the experimental conditions for surface roughness. The study results imply that the feed rate and tool nose radius significantly affected the surface quality, but the spindle speed did not. The linear regression model is valid to forecast the surface roughness. The cutting parameters for optimum surface quality are a combination of a spindle speed of 710 rpm, a feed rate of 0.052 mm/rev and a tool nose radius of 1.2 mm. The machined surface topography contains the feed marks, micro-voids, material side and material debris, but they become smaller and decrease at a lower feed rate, larger tool nose radius and higher spindle speed. These results show the good surface quality of magnesium alloys in a dry turning process, which could be applied in implant, orthopedic and trauma surgery.

Application of Calendering Process to Roll-to-Roll Printed Electronics

2011 ◽  
Vol 317-319 ◽  
pp. 436-439 ◽  
Author(s):  
Li Li Xin ◽  
Nguyen Ho Anh Duc ◽  
Nguyen Hoang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Printed Electronics ◽  
Experimental Results ◽  
Gravure Printing ◽  
Mechanical Pressure ◽  
Roll To Roll ◽  
Pet Film ◽  
Printing Machine

This paper presents the design of calendering machine and experimental results of calendering process. A particular pattern was printed on PET film by means of roll-to-roll gravure printing machine. The calendering process was applied to a set of samples and the effect was analyzed after measuring the surface roughness and the thickness of pattern. Although only mechanical pressure provided by a nip roll was applied during the calendering process, the experimental results indicate that the calendering process should be useful for enhancing the surface quality of roll-to-roll printed electronics products.

scholarly journals Experimental Research on the Surface Quality of Milling Contour Bevel Gears

2021 ◽  
Author(s):  
Mingyang Wu ◽  
Jianyu Zhang ◽  
Chunjie Ma ◽  
Yali Zhang ◽  
Yaonan Cheng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Defects ◽  
Low Noise ◽  
Tooth Surface ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Bevel Gears ◽  
Machined Surface Roughness

Abstract Contour bevel gears have the advantages of high coincidence, low noise and large bearing capacity, which are widely used in automobile manufacturing, shipbuilding and construction machinery. However, the quality of the tooth surface has a significant impact on the transmission accuracy of the gear, so it is of great significance to optimize the surface quality of the contour bevel gear. This paper firstly analyzes the formation process of machined surface roughness of contour bevel gears on the basis of generating machining method, and dry milling experiments of contour bevel gears are conducted to analyze the effects of cutting speed and feed rate on the machined surface roughness and surface topography of the workpiece. Then, the surface defects on the machined surface of the workpiece are studied by SEM, and the causes of the surface defects are analyzed by EDS. After that, XRD is used to compare the microscopic grains of the machined surface and the substrate material for diffraction peak analysis, and the effect of cutting parameters on the microhardness of the workpiece machined surface is investigated by work hardening experiment. The research results are of great significant for improving the machining accuracy of contour bevel gears, reducing friction losses and improving transmission efficiency.

Machined Surface Quality of Pre-Sintered Hardenable PM Steel

2015 ◽  
Vol 659 ◽  
pp. 335-339 ◽  
Author(s):  
Thawatchai Khantisitthiporn ◽  
Monnapas Morakotjinda ◽  
Bhanu Vetayanugul ◽  
Ruangdaj Tongsri
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Texture ◽  
Depth Of Cut ◽  
Hydraulic Pressure ◽  
Average Surface Roughness ◽  
Machined Surface ◽  
Average Surface ◽  
Machined Surface Quality

The benefit of pre-sintered machining is to avoid machining difficulty of sintered parts especially hardenable PM steels. Pre-sintering treatments of green PM part at temperatures lower than the normal sintering temperature of 1120 °C result in green strength improvement high enough for machining. In this study, the influences of various pre-sintering temperatures and several machining conditions on machined surface quality of pre-sintered PM samples were investigated. The pre-sintered samples were machined by a turning process using a carbide cutting insert with varied cutting speeds at a fixed feed rate and depth of cut without cutting lubricant. Chromium alloyed PM steel (Astaloy® CrM) powder samples with (0.5 wt. %C) and without graphite (0 wt. % C) additions mixed with 1 wt. % of zinc stearate were prepared as green parts by cold compaction in a cylindrical die with diameter of 30 mm. Green density was about 7.00 g/cm3 and height of each sample was controlled by hydraulic pressure and powder weight of 80 g/sample. The green samples were treated by pre-sintering treatment before machining testing. Surface quality of each machined sample was evaluated by average surface roughness and surface texture by SEM analysis and the appearance of outlet edge breakout. The experimental results revealed that the pre-sintered samples with graphite addition showed better surface quality in terms of surface roughness and surface texture and small outlet edge breakout appearance. Moreover, at high pre-sintering temperatures of 900 and 1,000°C, the samples showed similar average surface roughness under the same turning conditions. The obtained surface textures were better than those of the samples pre-sintered at 700 and 800°C. The outlet edge breakout could not be found in the graphite-added samples pre-sintering at 1,000°C.

Actively Cooled and Activated Coolant for Grinding Brittle Materials

2008 ◽  
Vol 389-390 ◽  
pp. 338-343 ◽  
Author(s):  
Y. Gao ◽  
J. Xin ◽  
H. Lai
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Surface Quality ◽  
Experimental Studies ◽  
Brittle Materials ◽  
Cryogenic Cooling ◽  
Experimental Results ◽  
Cooling Method ◽  
Cooling Methods

An actively cooled and activated cooling approach is proposed and examined in this project in order to deal with the problems associated with methods such as the cryogenic cooling method. It is also aimed to further improve the surface quality of the workpiece after grinding by combining the advantages of the existing cooling methods. Both computational and experimental studies were conducted for grinding the brittle materials with the proposed approach. Optical examinations were used to study the surface morphology. The experimental results show that the surface quality can be improved by up to 23.75% on average in terms of surface roughness Ra. The computational test reveals that the heat can be taken away more effectively by the proposed approach.

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