scholarly journals Improvement of Surface Quality based on Magnetorheological Fluids Flexible Fixture During Milling Thin-walled Parts

2021 ◽  
Author(s):  
Yong Zhang ◽  
Shan Gao ◽  
Ning Yang ◽  
Xiaohui Jiang ◽  
Guokuan Zhao ◽  
...  
Keyword(s):  
Surface Quality ◽  
Rotational Speed ◽  
Complex Structure ◽  
Point Contact ◽  
Feed Speed ◽  
Cutting Depth ◽  
Maximum Decrease ◽  
Speed Change ◽  
Thin Walled

Abstract Aerospace thin-walled parts have the characteristics of low stiffness and complex structure, which are easily deformed by machine tool vibration, cutting force and heat during machining. The traditional fixture is in point contact with the workpiece, and the workpiece bears uneven force, which results in poor surface quality and low precision of the part. Therefore, it is urgent to improve the machining efficiency and surface quality of workpiece. According to the performance of magnetorheological fluid, a magnetorheological flexible fixture is designed to completely wrap the parts so as to make them bear uniform force, improve the stiffness of the system and inhibit flutter. Firstly, the stiffness distribution of thin-walled parts, flexible fixtures and fixture-workpiece system is studied in this paper. It can be seen that the symmetrical center stiffness of magnetorheological flexible fixtures is relatively low. Through milling experiments with single process parameters, it is found that when the rotational speed, cutting depth and feed speed change, the composite clamping effect is better than the traditional clamping effect, in which with the increase of rotational speed, the vibration acceleration in Ax, Ay and Az directions decreases by 25.16%, 26.87% and 10.78% respectively; When the cutting depth increases, Ay decreases by 23.12% at the maximum. When the feed speed changes, it decreases by 15.78%. Finally, based on the case of milling thin-walled parts with magnetorheological flexible fixture, it is obtained that the coaxiality of composite clamped thin-walled parts decreases by 13.85%, and the maximum decrease of cylindricity is 36.73%. Roughness value Rz decreases by 80.47% at the maximum. In summary, the above results have verified that the machining quality of the magnetorheological flexible fixture is better.

scholarly journals Parameter Optimization of Polishing M300 Mold Steel with an Elastic Abrasive

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Xiao-Jun Wu ◽  
Xin Tong ◽  
Hao Sun ◽  
Huibo Jia ◽  
Lu Zhang
Keyword(s):  
Particle Size ◽  
Rotational Speed ◽  
Abrasive Particle ◽  
Polished Surface ◽  
Feed Speed ◽  
Range Analysis ◽  
Cutting Depth ◽  
Surface Polishing ◽  
Optimum Parameters ◽  
Influence Degree

In order to achieve high-quality polishing of M300 mold steel curved surface, an elastic abrasive is introduced in this paper, and its polishing parameters are optimized so that the mirror roughness can be achieved. Based on the Preston equation and Hertz contact theory, the theoretical material removal equation for surface polishing of elastic abrasives is obtained, and the polishing parameters to be optimized are as follows: particle size S, rotational speed Wt, cutting depth Ap, and feed speed Vf. The Taguchi method is applied to design the orthogonal experiment with four factors and three levels. The influence degree of various factors on the roughness of the polished surface and the combination of parameters to be optimized were obtained by the range analysis method. The particle swarm optimization algorithm optimizes the BP neural network algorithm (PSO-BP), which is used to optimize the polishing parameters. The results show that the rotational speed has the greatest influence on the roughness, the influence degree of abrasive particle size is greater than that of feed speed, and the influence of cutting depth is the least. The optimum parameters are as follows: particle size S 1200#, rotational speed Wt 4500rpm, cutting depth Ap 0.25mm, and feed speed Vf 0.8mm/min. The roughness of the surface polishing with optimum parameters is reduced to 0.021 μm.

scholarly journals Research on the Influencing Factors of "Scale Veins" of Single Point Incremental Forming Workpieces Surface

2015 ◽  
Vol 9 (1) ◽  
pp. 1025-1032
Author(s):  
Shi Pengtao ◽  
Li Yan ◽  
Yang Mingshun ◽  
Yao Zimeng
Keyword(s):  
Surface Quality ◽  
Incremental Forming ◽  
Single Point ◽  
Spindle Speed ◽  
Experimental Results ◽  
Feed Speed ◽  
Single Point Incremental Forming ◽  
Machining Parameters ◽  
The Mathematical Model

To furthermore optimize the machining parameters and improve the surface quality of the workpieces manufactured by single point incremental forming method, the formation mechanism of the sacle veins on the metal incremental froming workpieces was studied through experiment method. The influence principle of the spindle speed, the feed speed and the material of tip of tools on the length of scale veins was obtained through analyzing the experimental results and building the mathematical model among the length of scale veins were feed speed and spindle speed through measuring the roughness of surfaces and observing the appearance of the forming workpieces. The experimental results showed that, the spindle speed, the feed speed and the material of tool tips have a significant effect on the scale veins formation on the surface of forming workpieces. Therefore, an appropriate group of spindle speed and feed speed can reduce the effect of scale veins on the roughness of single point incremental forming workpieces and furthermore improve the surface quality of forming workpieces.

scholarly journals Effect of High Speed Milling Process Parameters on the Milling Force and Surface Topography of AM50A Magnesium Alloy

2018 ◽  
Vol 36 (1) ◽  
pp. 124-131
Author(s):  
Hongji Zhang ◽  
Yuanyuan Ge ◽  
Hong Tang ◽  
Yaoyao Shi ◽  
Zengsheng Li
Keyword(s):  
Magnesium Alloy ◽  
Surface Quality ◽  
High Speed ◽  
Milling Process ◽  
Spindle Speed ◽  
Feed Speed ◽  
Milling Force ◽  
High Speed Milling ◽  
Milling Parameters

Within the scope of high speed milling process parameters, analyzed and discussed the effects of spindle speed, feed rate, milling depth and milling width on milling forces in the process of high speed milling of AM50A magnesium alloy. At the same time, the influence of milling parameters on the surface roughness of AM50A magnesium alloy has been revealed by means of the measurement of surface roughness and surface micro topography. High speed milling experiments of AM50A magnesium alloy were carried out by factorial design. Form the analysis of experimental results, The milling parameters, which have significant influence on milling force in high speed milling of AM50A magnesium alloy, are milling depth, milling width and feed speed, and the nonlinear characteristics of milling force and milling parameters. The milling force decreases with the increase of spindle in the given mill parameters. For the effects of milling parameters on surface quality of the performance, in the milling depth and feeding speed under certain conditions with the spindle speed increases the surface quality of AM50A magnesium alloy becomes better with the feed speed increases the surface quality becomes poor. When the spindle speed is greater than 12000r/min, the milling depth is less than 0.2mm, and the feed speed is less than 400mm/min, the milling surface quality can be obtained easily.

Fractal-Based Analysis of the Relation Between Surface Finish and Machine Vibration in Milling Operation

2019 ◽  
Vol 19 (01) ◽  
pp. 2050006 ◽  
Author(s):  
Muhammad Owais Qadri ◽  
Hamidreza Namazi
Keyword(s):  
Surface Quality ◽  
Complex Structure ◽  
Vibration Signal ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Machined Surface ◽  
Machine Vibration ◽  
Milling Operation ◽  
Surface Changes

Analysis of surface quality of machined workpiece is an important issue in machining of materials. For this purpose, scientists analyze how the texture of machined surface changes due to different conditions. Machine vibration is one of the factors that highly affects the surface quality of machined surface. In this research, we analyze the relation between machine vibration and surface quality of machined workpiece. For this purpose, we employ fractal theory and analyze how the complex structure of machined surface changes with the complex structure of machine vibration signal in case of variations of machining parameters, namely, depth of cut, feed rate and spindle speed, in milling operation. Based on the results, variations of surface quality of machined workpiece are related with the variations of complexity of machine vibration signal. The method of analysis employed in this research can be applied to other machining operations in order to find the relation between machine vibration and surface quality of 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.

Research of Grinding Material Tools by Modern Grinding Wheels

2013 ◽  
Vol 581 ◽  
pp. 211-216 ◽  
Author(s):  
Jiří Čop ◽  
Imrich Lukovics
Keyword(s):  
Boron Nitride ◽  
Surface Quality ◽  
High Surface ◽  
Cubic Boron Nitride ◽  
High Accuracy ◽  
Grinding Wheels ◽  
Cutting Depth ◽  
High Surface Quality ◽  
Materials Used

This research paper focuses on grinding of materials used for tools (100Cr6 (CSN 4 14109), X210Cr12 ( CSN 4 19436) and epoxy resin) using grinding wheels from cubic boron nitride and diamond. The disadvantage of grinding of difficult-to-machine materials is higher wear of grinding wheels. The modern grinding wheels are able to achieve high accuracy of dimensions and high surface quality with a smaller wear of grinding wheels then grinding wheels from conventional materials. Correctly selected technological conditions are one of the most important matters to achieve the required surface quality. The main aim of this research is to determine the influence of technological conditions to quality of surface after planar grinding. The research determines the influence of the grain type of grinding wheels, feed rate and cutting depth on the quality of functional surfaces.

Study on Surface Roughness of Milling In-Situ TiB2 Particle Reinforced Al Matrix Composites

2019 ◽  
Author(s):  
Xiao-fen Liu ◽  
Wen-hu Wang ◽  
Rui-song Jiang ◽  
Yi-feng Xiong ◽  
Kun-yang Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Metal Matrix ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Matrix Composites ◽  
Cutting Depth

Abstract The current state of surface roughness focuses on the 2D roughness. However, there are shortcomings in evaluating surface quality of particle reinforced metal matrix composites using 2D roughness due to the fact that the measuring direction has a vital impact on the 2D roughness value. It is therefore of great importance and significance to develop a proper criterion for measuring and evaluating the surface roughness of cutting particle reinforced metal matrix composites. In this paper, an experimental investigation was performed on the effect of cutting parameters on the surface roughness in cutting in-situ TiB2/7050Al MMCs. The 2D roughness Ra, 3D roughness Sa and Sq were comparatively studied for evaluating the machined surface quality of in-situ TiB2/7050Al MMCs. The influence of cutting parameters on the surface roughness was also analyzed. The big difference between roughness Ra measured along cutting and feed directions showed the great impact of measuring direction. Besides, surface defects such as pits, grooves, protuberances and voids were observed, which would influence 2D roughness value greatly, indicating that 3D roughness was more suitable for evaluating surface quality of cutting in-situ TiB2/7050Al MMCs. The cutting depth and feed rate were found to have the highest influence on 3D roughness while the effect of cutting speed was minimal. With increasing feed rate, cutting depth or width, the 3D roughness increased accordingly. But it decreased as cutting speed increased.

DECODING OF THE RELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950054 ◽  
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI AKHAVAN FARID ◽  
TECK SENG CHANG
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Surface Quality ◽  
End Milling ◽  
Complex Structure ◽  
Dry Machining ◽  
End Mill ◽  
Milling Operation ◽  
Machining Operations

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

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.

FRACTAL-BASED ANALYSIS OF THE EFFECT OF MACHINING PARAMETERS ON SURFACE FINISH OF WORKPIECE IN TURNING OPERATION

Fractals ◽  
2019 ◽  
Vol 27 (04) ◽  
pp. 1950043 ◽  
Author(s):  
GEEVIN JITHMAL PATHIRANAGAMA ◽  
HAMIDREZA NAMAZI
Keyword(s):  
Surface Quality ◽  
Surface Finish ◽  
Feed Rate ◽  
Fractal Theory ◽  
Complex Structure ◽  
Spindle Speed ◽  
Machining Parameters ◽  
Cutting Depth ◽  
Machined Surface ◽  
Turning Operation

Analysis of workpiece surface quality is one of the major issues in manufacturing engineering. Turning operation is a famous machining operation that is widely used in machining of materials. In this research, we investigate the surface finish of machined workpiece from turning operation. For this purpose, we employ fractal theory to study the complex structure of machined workpiece’s surface in different conditions. The applied parameters include the variations of cutting depth, feed rate and spindle speed in wet and dry machining conditions. Based on the obtained results, we found the correlation between the increment of fractal dimension of machined surface and the increment of cutting depth, feed rate and spindle speed in wet machining condition. The obtained results will be discussed in relation with the complexity of machined surface. The employed method of analysis in this research can be widely applied to the analysis of the effect of different machining parameters and conditions on the surface quality of machined workpiece in case of different machining operations.

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