Experimental Study on Vibration-Assisted Grinding

Author(s):  
Kuan-Ming Li ◽  
Yang-Ming Hu ◽  
Zhong-Yi Yang ◽  
Ming-Yuan Chen

This paper presents experimental studies of vibration-assisted grinding with small-amplitude vibration (in the order of 1 μm) in terms of ground surface finish and tool life. The objectives are to obtain finer surface finishes on molds and longer tool life. The investigation shows that vibration-assisted grinding can improve surface finishes when compared with conventional grinding. Two different vibration frequencies are conducted in the experiments. Results show that surface finish and tool life are influenced by different process parameters. In vibration-assisted grinding, the best surface finish is obtained by using higher frequency of 11.4 kHz and lower feed rates. In this study, vibration-assisted grinding can extend tool life more than twice as that in conventional grinding. It is also shown that tool life in vibration-assisted grinding can be significantly improved by using minimum quantity lubrication (MQL).

2013 ◽  
Vol 845 ◽  
pp. 889-893
Author(s):  
A.E.I. Elshwain ◽  
Norizah Redzuan

Advanced materials like nickel and titanium have unique combinations such as low thermal conductivity, high chemical reactivity, and high hardness. Machining these materials requires suitable lubricant and proper cooling technique for increasing tool life, decreasing cutting temperature, and improving surface roughness. This paper presents a brief review done on gas-based coolant-lubricants (CLs) used in the form of either gas or cooled-pressured air and gases. Main gas-based CLs are air, N2, and CO2. Investigations of previous researches include hypered cooled air (at different cooling temperatures), minimum quantity lubrication (MQL), and gases which have been used on machining operation that affect tool life and surface finish. Compresed N2 and cooled air with MQL was identified as the most suitable coolant-lubricants for machining performance. Furthermore, this type of gas-based coolant-lubricant (CLs) is considered as one of the environmentally conscious machining.


2015 ◽  
Vol 9 (2) ◽  
pp. 176-183 ◽  
Author(s):  
Kazuhito Ohashi ◽  
◽  
Kazuya Tan ◽  
Tomoya Ashida ◽  
Shinya Tsukamoto

In mass production cylindrical grinding operations, the ground surface finish has never been measured in each grinding cycles because existing surface roughness testers take a relatively long time to measure surface finishes, and the introduction of a surface roughness tester in each grinding cycle would affect mass production processes. Therefore, the surface finish of all parts manufactured in a production lot is generally evaluated based on the measured results of only few parts by sampling checks. We have proposed a unique quick technique for measuring surface roughness. It uses electromotive force based on the slight frictional heat to evaluate the surface finish of cylindrical workpieces rotating on cylindrical grinding machines, and it can do this in a split second just after each grinding cycle, so it does not hamper mass production grinding processes. The proposed quick measurement system can capture the variations in surface finish in a set of repeated cylindrical grinding cycles without dressing. The possibility of accurate judging dressing time by using the quick measurement system in mass production grinding processes is shown experimentally.


Author(s):  
Er. Sher Singh

In modern production industries, main focus is on high productivity with best surface finish. For this purpose use of cutting fluid in machining of component plays major role in controlling the surface finish of components. The cutting fluids are generally applied continually during machining i.e. wet or flooded machining. The dry machining yields poor surface finish and less tool life whereas wet machining results in better surface finish as well as longer tool life. But continuous lubrication involves very large amount of consumption of cutting fluids which cause health hazards of machining operator and ill effects on environment. Moreover, continuous lubrication contributes to increase in total production cost of product. Hence, the Minimum Quantity Lubrication(MQL) is needed nowadays which works with less amount of cutting fluid (100-1000ml/hr) with pressurized air (as mist form) as compare wet machining (amount of cutting fluid 400-500L/hr approx.). The study focus on comparison of surface roughness behavior of AL-6061 under different lubrication conditions i.e. Dry, Wet and MQL. The experimental work performed on CNC milling machine involving cutting parameters feed rate, spindle speed and depth of cut as input parameters, where surface roughness and microstructure of specimens were observed as output parameters in the experiment. The machined components under different conditions i.e. DCM (dry cutting machining), MQL (minimum quantity lubrication), WCM (wet cutting machining) were examined for surface roughness using R-10 surface roughness tester whereas microstructure analysis was done using optical microscope. For given cutting parameters at 2000RPM spindle speed, 200mm/min. feed rate and it is found that better result of MQL from the dry machining and nearest of wet machining.


Alloy Digest ◽  
1993 ◽  
Vol 42 (9) ◽  

Abstract PRODEC STAINLESS TYPE 316 is a standardized grade in plate and bar with an improved machining capability over the conventional AISI Type 316. It is a product of extensive laboratory testing and application proven. Its improved machinability offers: shorter machining time; longer tool life; better surface finish; less distortion problems; more homogeneity in microstructures; and marginally increased resistance to corrosion. This datasheet provides information on composition and physical properties. It also includes information on machining. Filing Code: SS-549. Producer or source: Avesta Sheffield Inc.


2021 ◽  
Vol 5 (2) ◽  
pp. 42
Author(s):  
Abdelkrem Eltaggaz ◽  
Ibrahim Nouzil ◽  
Ibrahim Deiab

Minimum Quantity Lubrication nanofluid (MQL-nanofluid) is a viable sustainable alternative to conventional flood cooling and provides very good cooling and lubrication in the machining of difficult to cut materials such as titanium and Inconel. The cutting action provides very difficult conditions for the coolant to access the cutting zone and the level of difficulty increases with higher cutting speeds. Furthermore, high compressive stresses, strain hardening and high chemical activity results in the formation of a ‘seizure zone’ at the tool-chip interface. In this work, the impact of MQL-nanofluid at the seizure zone and the corresponding effects on tool wear, surface finish, and power consumption during machining of Ti-6Al-4V was investigated. Aluminum Oxide (Al2O3) nanoparticles were selected to use as nano-additives at different weight fraction concentrations (0, 2, and 4 wt.%). It was observed that under pure MQL strategy there was significant material adhesion on the rake face of the tool while the adhesion was reduced in the presence of MQL-nanofluid at the tool-chip interface, thus indicating a reduction in the tool chip contact length (TCCL) and reduced seizure effect. Furthermore, the flank wear varied from 0.162 to 0.561 mm and the average surface roughness (Ra) varied from 0.512 to 2.81 µm. The results indicate that the nanoparticle concentration and the reduction in the seizure zone positively influence the tool life and quality of surface finish.


Author(s):  
Andres F. Clarens ◽  
Ye-Eun Park ◽  
Jacob Temme ◽  
Kim Hayes ◽  
Fu Zhao ◽  
...  

Carbon Dioxide is an industrial byproduct that has been proposed as an alternative metalworking fluid (MWF) carrier with lower environmental impacts and better cooling potential than existing MWFs. This paper investigates the heat removal and tool life effects of rapidly expanding supercritical CO2 (scCO2)-based MWFs relative to MWFs delivered as a flood of semi-synthetic emulsion or as minimum quantity lubrication (MQL) sprays. When cutting both compacted graphite iron (CGI) and titanium, tool wear was most effectively controlled using the scCO2-based MWF compared with the other MWFs. Analysis in this paper suggests that the performance benefit imparted by rapidly expanding scCO2 appears to be related to both the cooling potential and penetration of the sprays into the cutting zone. High-pressure gas sprays have lower viscosity and higher velocity than conventional MWFs. An experiment in which the spray direction was varied clearly demonstrated the importance of spray penetration in tool wear suppression. The type of gas spray is also a significant factor in tool wear suppression. For instance, a spray of N2 delivered under similar conditions to CO2 effectively reduced tool wear relative to water based fluids, but not as much as CO2. This result is particularly relevant for MQL sprays which are shown to not cool nearly as effectively as scCO2 MWFs. These results inform development of scCO2-based MWFs in other machining operations, and provide insight into the optimization of scCO2 MWF delivery.


2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.


2021 ◽  
Vol 114 ◽  
pp. 116-124
Author(s):  
Gabriela Slabejová ◽  
MÁRIA ŠMIDRIAKOVÁ

Colour stability of surface finishes on thermally modified beech wood. The paper deals with the influence of the type of transparent surface finish on the change of colour of the surfaces of native beech wood and thermally modified wood. At the same time, the colour stability of three surface finishes on the surfaces of native and thermally modified beech wood was monitored. Beech wood was thermally modified at temperature of 125 °C for 6 hours. The thermal treatment was performed in a pressure autoclave APDZ 240, by the company Sundermann s.r.o in Banská Štiavnica. Three various types of surface finishes (synthetic, wax-oil, water-based) were applied onto the wood surfaces. The colour of the surfaces of native wood and thermally modified wood was measured in the system CIELab before and after surface finishing; the coordinates L*, a*, b*, C*ab and h*ab were measured. From the coordinates measured before and after surface finishing, the differences were calculated and then the colour difference ∆E* was calculated. Subsequently, the test specimens with the surface finishes were exposed to natural sunlight, behind glass in the interior for 60 days. The surface colour was measured at specified time of the exposure (10, 20, 30, 60 days). The results showed that the colour of the wood surfaces changed after application of the individual surface finishes; and the colour difference reached a change visible with a medium quality filter up to a high colour difference. The wax-oil surface finish caused a high colour difference on native wood and on thermally modified wood as well. On native beech wood, the lowest colour difference after exposure to sunlight was noticeable on the synthetic surface finish. On the surface of wood thermally modified, after exposure to sunlight, the lowest colour difference was noticeable on the surface with no surface finish.


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771061 ◽  
Author(s):  
Duc Tran Minh ◽  
Long Tran The ◽  
Ngoc Tran Bao

In this article, an attempt has been made to explore the potential performance of Al2O3 nanoparticle–based cutting fluid in hard milling of hardened 60Si2Mn steel (50-52 HRC) under different minimum quantity lubrication conditions. The comparison of hard milling under minimum quantity lubrication conditions is done between pure cutting fluids and nanofluids (in terms of surface roughness, cutting force, tool wear, and tool life). Hard milling under minimum quantity lubrication conditions with nanofluid Al2O3 of 0.5% volume has shown superior results. The improvement in tool life almost 177%–230% (depending on the type of nanofluid) and the reduction in surface roughness and cutting forces almost 35%–60% have been observed under minimum quantity lubrication with Al2O3 nanofluids due to better tribological behavior as well as cooling and lubricating effects. The most outstanding result is that the uncoated cemented carbide insert can be effectively used in machining high-hardness steels (>50 HRC) while maintaining long tool life and good surface integrity (Ra = 0.08–0.35 µm; Rz = 0.5–2.0 µm, equivalent to finish grinding) rather than using the costlier tools like coated carbide, ceramic, and (P)CBN. Therefore, using hard nanoparticle–reinforced cutting fluid under minimum quantity lubrication conditions in practical manufacturing becomes very promising.


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