scholarly journals Study on high quality surface finishing technology of pre-spinning nozzle in additive manufacturing

2021 ◽  
Vol 39 (2) ◽  
pp. 334-340
Author(s):  
Weiwei Liu ◽  
Qian Lyu ◽  
Liming Lei ◽  
Yanhao Hou ◽  
Lei Shi
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Abrasive Particle ◽  
Processing Parameters ◽  
Surface Finishing ◽  
Range Analysis ◽  
Typical Structure ◽  
Surface Polishing ◽  
Before And After ◽  
Polishing Tool

Through the simulation of abrasive flow in the inner cavity of the superalloy pre-spinning nozzle made by additive manufacturing, the special abrasive polishing tool is optimized and the surface polishing technology of the inner cavity of typical structure test pieceis studied. Through comparison of the surface morphology before and after polishing, it can be concluded that the abrasive flow has a considerable removal effect on the powder sticking effect, spheroidizing effect, step effect, slag hanging phenomenon and residual support on the surface of parts, but it has a limited effect on the surface pit of the substrate. After polishing, the surface roughness of the inner cavity of parts decreasea from Ra 3.1397 μm to Ra 0.5805 μm, and the surface roughness of blade position decreases from Ra 4.8473 μm to Ra 0.3606 μm. Through the range analysis, it is found that the effect intensity of the processing parameters on the surface roughness of the parts is in order of the processing time, processing pressure and abrasive particle size.

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 Study on the Electrorheological Ultra-Precision Polishing Process with an Annular Integrated Electrode

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1235
Author(s):  
Cheng Fan ◽  
Yigang Chen ◽  
Yucheng Xue ◽  
Lei Zhang
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Applied Voltage ◽  
Abrasive Particle ◽  
Polishing Process ◽  
Workpiece Surface ◽  
Orthogonal Experiments ◽  
Single Process ◽  
Ultra Precision ◽  
Polishing Tool

Electrorheological (ER) polishing, as a new ultra-precision super-effect polishing method, provides little damage to the workpiece surface and is suitable for polishing all kinds of small and complex curved surface workpieces. In this paper, an ER polishing tool with an annular integrated electrode is developed. The orthogonal experiments are carried out on the six influencing factors of ER polishing which include the applied voltage, the abrasive particle size, the abrasive concentration, the polishing gap, the polishing time and the tool spindle speed. The influence order of these six factors on the ER polishing is obtained. On this basis, the effect of a single process parameter of ER polishing on surface roughness is studied experimentally.

Quartz Wafer Machining Using MCF (Magnetic Compound Fluid) Polishing Liquid Frozen with Liquid Nitrogen

2008 ◽  
Vol 389-390 ◽  
pp. 187-192
Author(s):  
Yong Bo Wu ◽  
Kunio Shimada
Keyword(s):  
Surface Roughness ◽  
Liquid Nitrogen ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Abrasive Particles ◽  
Water Based ◽  
Quartz Wafer ◽  
Polishing Tool

This paper deals with the machining of quartz wafers using an MCF (Magnetic Compound Fluid) polishing liquid, frozen with liquid nitrogen. This type of polishing liquid is composed of water-based MF (Magnetic Fluid), iron powder, abrasive particle and α-cellulose, and consequently reacting to magnetic fields. Experiments of polishing quartz wafers using the MCF method were carried out on a previously developed apparatus. The results show that an MCF polishing liquid, frozen with liquid nitrogen, has greater material removal capability than one that has not been frozen. A frozen MCF polishing liquid containing larger abrasive particles yields a higher material removal rate, however the surface roughness deteriorates. The highest material removal rate and the best surface roughness were obtained when the percentage of water, in the frozen MCF polishing tool, was 34.7%.

scholarly journals Fatigue Life Testing of Locally Additive Manufactured AlSilOMg Test Specimens

R&D Journal ◽  
2021 ◽  
Vol 37 ◽  
Author(s):  
N. Agenbag ◽  
C. McDuling
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Additive Manufacturing ◽  
Surface Finish ◽  
Material Properties ◽  
Fatigue Testing ◽  
Fatigue Tests ◽  
Surface Finishing ◽  
Test Results ◽  
Static Testing

ABSTRACT In order for additive manufacturing to become a viable manufacturing methodfor aerospace engineering, it is required that exhaustive static and fatigue testing be performed. The testing is required in order to describe material properties in a statistical manner. Fatigue tests were performed on standard additive manufactured ASTM E466 test specimens in order to obtain the low (1000 cycles) to high cycle (1E6 cycles) behaviour of AlSi10Mg. The specimens were manufactured using non-heat treated, but stress relieved specimens. Specimens were printed in three build directions, namely the XY (parallel with build plate), 45 degree and vertical direction as measured with respect to the build baseplate. The three different directions were chosen to investigate the sensitivity of the material properties to the build direction. The specimens were stress relieved on the baseplate. Static testing was also performed on specimens according to ASTM E8/E8M. The specimens were produced to have a surface finish representative of standard deburring techniques used in the aerospace industry. The surface roughness on the specimens were measured. The scatter in test data as a result of the surface finish on material properties is quantified. It is a requirement to quantify the effect of the surface roughness on fatigue failure allowable values since a machined type finish (less than 3.2 micrometer) is not always practically possible to achieve with additive manufactured structures. This is because the organic shapes produced with additive manufacturing makes some surfaces inaccessible to normal surface finishing techniques. Furthermore, some internal structures such as lattice structures are completely inaccessible to surface finishing techniques such as polishing or lapping. In addition to the surface roughness the roundness of the test section was also measured using inspection equipment. This was required since the industrial deburring techniques did not yield a completely concentric test section as a lathe operation would produce. Once again this is representative of an additive manufactured structure. The fatigue tests were performed at an R-ratio of 0.1. The test results were used to produce Wöhler or S-N curves for the material in all three material directions. The scatter was quantified using industry accepted methods. The results were compared with fatigue test results from literature of specimens produced with a lathe in order to compare a practical industrial surface finish on an additive manufactured component with a machined surface finish. It was found that the build support structures of the additive manufacturing process causes stress concentrations in the fatigue test specimens. This leads to a reduction in fatigue life and an increase in the scatter of the results. Additional keywords: Additive manufacturing, fatigue testing, static testing, aluminium, AlSi10Mg.

scholarly journals Improving the surface quality and mechanical properties of selective laser sintered PA2200 components by the vibratory surface finishing process

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Hamaid M. Khan ◽  
Tolga B. Sirin ◽  
Gurkan Tarakci ◽  
Mustafa E. Bulduk ◽  
Mert Coskun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Microstructural Analysis ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Surface Finishing ◽  
Finishing Process ◽  
Wide Range

Abstract This paper attempts to improve the physical and mechanical properties of selective laser sintered polyamide PA2200 components through a vibratory surface finishing process by inducing severe plastic deformation at the outer surface layers. The industrial target of additive manufacturing components is to obtain structures having surface roughness, hardness, and other mechanical properties equivalent to or better than those produced conventionally. Compared to the as-built SLS PA2200 samples, vibratory surface finishing treated specimens exhibited a smooth surface microstructure and more favorable roughness, hardness, and tensile strength. Also, the duration of the vibratory surface finishing process showed a further improvement in the surface roughness and hardness of the SLS samples. Compared to the as-built state, the roughness and hardness of the surface-treated samples improved by almost 90% and 15%, respectively. Consequently, microstructural analysis indicates that lower surface roughness and enhanced surface hardness is a crucial factor in influencing the overall tensile strength of SLS-PA2200 components. We consider that the combination of VSF and SLS processes can successfully handle a wide range of potential applications. This study also highlights the efficiency and applicability of the vibratory surface finishing process to other additive manufacturing processes and materials. Graphic abstract

Surface Finishing of Single-Crystal SiC and GaN Wafers Using a Magnetic Tool in H2O2Solution

2019 ◽  
Vol 13 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Akihisa Kubota ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Removal Rate ◽  
Hydrogen Peroxide Solution ◽  
Surface Finishing ◽  
Oh Radicals ◽  
Atomic Step ◽  
Convex Part ◽  
Atomic Force ◽  
Before And After

To remove the microroughness and subsurface damage on the SiC and GaN surface efficiently, a surface finishing technique using a magnetic tool holding iron particles in a hydrogen peroxide solution is developed. This technique utilizes OH radicals generated from the iron catalytic particles in a hydrogen peroxide solution, and can be used to preferentially remove the topmost convex part on the surface, resulting in an atomically smooth surface. We employed this polishing technique to finish the surfaces of 2-inch SiC and 2-inch GaN wafers. The surface roughness before and after finishing was measured by scanning white light interferometric microscopy and atomic force microscopy. In addition, the material removal rate was calculated by weight loss due to the finishing process. The results show that the surface roughness on the SiC and GaN wafers is markedly improved. Moreover, the surface waviness and flatness of these wafers before and after finishing did not deteriorate. Atomic force microscope images indicate that an atomically flat SiC surface with a roughness value below 0.1 nm RMS and a GaN surface with atomic step and terrace structures were achieved. Our proposed finishing technique is effective in improving the surface microroughness of SiC and GaN wafers.

Ultra Precision Surface Finishing Processes

2019 ◽  
Vol 13 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Fang-Jung Shiou ◽  
Assefa Asmare Tsegaw ◽  
◽  
Keyword(s):  
Surface Roughness ◽  
Optical Glass ◽  
Load Cell ◽  
Cnc Machining ◽  
Machining Process ◽  
Surface Finishing ◽  
Cnc Machine ◽  
Ball Burnishing ◽  
Finishing Processes ◽  
Polishing Tool

Surfaces of different complex shapes are aspirated part of many scientific measuring devices, medical, astronomical, and other precision activity utilizations. Components at miniaturized level should meet required surface roughness for the intended applications. Surface finishing of freeform and miniaturized components are always difficult and need to look for a new way out. In this study, an attempt was made to improve surfaces roughness of selected, most frequently used, engineering materials using different innovative processes, which can be integrated with CNC machine centers. An advanced automated surface finishing tools such as ball burnishing embedded with load cell, vibration assisted polishing, and self-propelled abrasive multi-jet polishing tools are proposed. Ball burnishing is advantageous for pre-machining process of ball polishing. Using the polishing device embedded with load cell, the constant force polishing is achieved. To reduce the volumetric wear of a polishing ball, vibration assisted polishing device is also integrated. Moreover, self-propelled abrasive multi-jet polishing tool, which achieves 93.33% improvement of surface roughness for lapped optical glass of BK7 has been subjugated from Ra 0.300 μm to 0.020 μm. These tools can be miniaturized and applicable in small micro CNC machining centers.

Surface Tribology Study Resulting by Diamond-Like Carbon Coating

2014 ◽  
Author(s):  
Sergio Mordo ◽  
Valery Popravko ◽  
Ahmad Barari
Keyword(s):  
Surface Roughness ◽  
Experimental Methodology ◽  
Surface Finishing ◽  
Coating Process ◽  
Uncoated Surface ◽  
Before And After ◽  
Coating Methods ◽  
Coated Surface ◽  
Materials Used ◽  
Mathematical Relationships

Companies that coat their products with DLC often have strict surface roughness and goals. This research investigates the surface roughness properties of uncoated and DLC coated specimens in an effort to know what uncoated surface roughness is needed to obtain a certain DLC coated surface roughness. Therefore, a model describing the relationship between uncoated and DLC coated surface roughness is needed. If this relationship can be estimated, the cost of surface finishing can be minimized by avoiding any unnecessary processes. A total of 7 specimens were tested before and after coating process with a non-contact surface roughness measurement microscope. Mathematical relationships are found between the DLC coated surface roughness and uncoated surface roughness. An experimental methodology was described for applying the findings to other coating methods and materials as the mathematical relationships found in this study are specific to the coating process and materials used.

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