Perbedaan Distribusi Kekerasan Metode Minimum Quantity Lubrication (MQL) dan Metode Wet Machining Pada Material Al-Zn

This study aims to determine the influence of three different coolant delivery methods, namely dry machining, Minimum Quantity Lubrication (MQL), and wet machining. This is quantitative research with the use of experimental methods. Data were collected through observation. Data analysis techniques being used was descriptive statistics. In MQL methods, the use of coolant is minimized by mixing it with high-pressurized air. It is shown from the obtained data that the use of MQL methods is not as good as the wet machining. The hardness distribution of wet machining method is lower than the MQL. This was observed from the machining chips of the two methods. The chips from the MQL method were darker than the wet machining method. This finding showed that the heat generated from the MQL was higher than that of wet machining. The Al and Zn bonds in the MQL method is considered to be denser.Penelitian ini bertujuan untuk mengetahui seberapa besar pengaruh penggunaan metode pemberian coolant yang berbeda, 3 metode yang digunakan adalah metode dry machining, Minimum Quantity Lubrication (MQL), dan wet machining. Penelitian ini termasuk jenis penelitian kuantitatif dan menggunakan metode eksperimen. Untuk teknik pengumpulan data menggunakan metode observasi dan teknik analisis data menggunakan teknik analisis statistik deskriptif. Metode MQL merupakan metode yang digunakan untuk meminimalisir penggunaan coolant dengan mencampurkannya dengan udara bertekanan tinggi. Data yang didapat menunjukkan bahwa penggunaan metode MQL belum sebaik penggunaan metode wet machining. Distribusi kekerasan metode wet machining lebih rendah daripada MQL. Hal tersebut dapat terlihat dari geram yang dihasilkan oleh kedua penggunaan metode tersebut, geram yang dihasilkan dari metode MQL lebih gelap daripada metode wet machining. Hal tersebut menunjukkan bahwa, panas yang dihasilkan dari metode MQL lebih tinggi daripada panas yang dihasilkan dari metode wet machining panas tersebut mempengaruhi ikatan Al dan Zn pada metode MQL menjadi lebih rapat.

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Study on the Effects of Abrasive and Coolant-Lubricant Types on Minimum Quantity Lubrication-MQL Grinding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.325.231 ◽

2011 ◽

Vol 325 ◽

pp. 231-237 ◽

Cited By ~ 7

Author(s):

Taghi Tawakoli ◽

M.J. Hadad ◽

A. Daneshi ◽

M.H. Sadeghi ◽

B. Sadeghi

Keyword(s):

Surface Quality ◽

Minimum Quantity Lubrication ◽

Dry Machining ◽

Grinding Forces ◽

Minimum Quantity ◽

Mql Grinding ◽

Air Jet ◽

Dry Grinding ◽

Surface Damages ◽

Minimum Quantity Lubricant

In dry grinding, as there is no coolant lubricant to transfer the heat from the contact zone, generation of surface damages are not preventable. Promising alternatives to conventional flood coolant applications are also Minimum Quantity Lubricant (MQL) or Near Dry Machining (NDM) or Semi Dry Machining (SDM). This research has been conducted to study the influence of the abrasive and coolant-lubricant types on the minimum quantity lubrication (MQL) grinding performance. One type of CBN and three types of conventional wheels (corundum) were tested. The tests were carried out in presence of fluid, air jet and eleven types of coolant-lubricants, as well as in dry condition. The results indicate that the finest surface quality and the lowest grinding forces could be obtained when grinding with CBN wheels. In the case of conventional wheels, the coarser wheel induces much proper grinding results.

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A review of near dry machining/minimum quantity lubrication machining of difficult to machine alloys

International Journal of Machining and Machinability of Materials ◽

10.1504/ijmmm.2016.076276 ◽

2016 ◽

Vol 18 (3) ◽

pp. 213 ◽

Cited By ~ 11

Author(s):

Talwinder Singh ◽

Pragat Singh ◽

J.S. Dureja ◽

Manu Dogra ◽

Harwinder Singh ◽

...

Keyword(s):

Minimum Quantity Lubrication ◽

Dry Machining ◽

Minimum Quantity

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EXPERIMENTAL ANALYSIS AND OPTIMIZATION OF THE CONTROLLABLE PARAMETERS IN TURNING OF EN AW-2011 ALLOY; DRY MACHINING AND ALTERNATIVE COOLING TECHNIQUES

Facta Universitatis Series Mechanical Engineering ◽

10.22190/fume191024009j ◽

2020 ◽

Vol 18 (1) ◽

pp. 013

Author(s):

Sonja Jozić ◽

Ivana Dumanić ◽

Dražen Bajić

Keyword(s):

Surface Roughness ◽

Cutting Force ◽

Material Removal Rate ◽

Material Removal ◽

Removal Rate ◽

Minimum Quantity Lubrication ◽

Cutting Parameters ◽

Dry Machining ◽

Cold Air ◽

Minimum Quantity

The latest trends in machining research show that great efforts are being made to understand the impact of different cooling and lubrication techniques as well as cutting parameters on machining performances. This paper presents the investigation results of different cutting parameters and different cutting environments such as dry machining, minimum quantity lubrication (MQL) and minimum quantity lubrication with compressed cold air (MQL+CCA) on average surface roughness, cutting force and material removal rate. The experiments were designed based on three input parameters and three different cutting environments when turning of EN AW-2011 alloy. Taguchi-based grey relational analysis was used to identify the optimal process parameters by which minimum values of surface roughness, minimum value of cutting force and maximum value of material removal rate will be achieved. The results showed that minimum quantity lubrication in the stream of compressed cold air, in comparison to dry and minimum quantity lubrication machining, gives the best machining performances. Therefore, the use of MQL + CCA method, which reduces the amount of lubricant may represent in the described extent of turning operations an alternative to turning processes most often carried out by wet method that causes considerable costs for purchasing, maintaining and using cutting fluids.

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Metacognitive awareness components of high-academic ability students in biology hybrid learning: Profile and correlation

Jurnal Pendidikan Biologi Indonesia ◽

10.22219/jpbi.v6i1.11097 ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Iin Hindun ◽

N. Nurwidodo ◽

Azizul Ghofar Candra Wicaksono

Keyword(s):

Quantitative Research ◽

Hybrid Learning ◽

Academic Ability ◽

Descriptive Statistics ◽

Metacognitive Awareness ◽

Learning Approach ◽

Analysis Techniques ◽

Learning Success ◽

Data Collection Instrument ◽

Metacognitive Awareness Inventory

Metacognitive awareness has been considered as one of the factors within students that determines learning success. It can be developed through a hybrid learning approach. The purpose of this quantitative research was to examine the metacognitive awareness profile of students with high-academic ability in hybrid learning implementation. The subjects of this study were the students of XI-Science class of state senior high school of Malang. The Metacognitive Awareness Inventory was used as the data collection instrument, while descriptive statistics and Pearson Product-Moment were chosen as the data analysis techniques. The results of the study informed that the students’ metacognitive awareness was divided into four categories, i.e. very good (9%), good (43%), enough (46%), and very low (2%). The three components of metacognitive awareness were classified as "enough", while the five components of students were categorized as "good". The eight metacognition components showed significant correlations each other (r > 0.41, n = 55, p < 0.01). It can be concluded that the majority of students’ metacognitive awareness was satisfactory even though there were a small proportion of students whose metacognitive awareness was not good.

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Analysis of Students' Critical Thinking Skills in Physics Problems

Kasuari Physics Education Journal (KPEJ) ◽

10.37891/kpej.v3i1.119 ◽

2020 ◽

Vol 3 (1) ◽

pp. 1-17

Author(s):

Tri Ariani

Keyword(s):

Critical Thinking ◽

Self Regulation ◽

Sampling Technique ◽

Thinking Skills ◽

Critical Thinking Skills ◽

Descriptive Statistics ◽

Observation Data ◽

Analysis Techniques ◽

The Subject ◽

High Ability Students

This study aims to determine the proportion of students' level of critical thinking skills on the subject of Impulse and Momentum, any difficulties experienced by students to reach the level of critical thinking skills, and solutions to overcome the difficulties of students achieving critical thinking skills. This research uses descriptive qualitative research methods. The subjects of this study were 27 students taken by purposive sampling technique. Data collection techniques in this study are tests of critical thinking skills, interviews, and observation. Data analysis techniques using descriptive statistics. The results showed that each student's ability, high ability students 36.84%, medium ability 34.50%, low ability 22.80% divided into two categories of KBK 2 with a percentage of 52.63% and KBK 1 with a percentage of 23, 94%. From the results of the study also obtained the achievement of students every KBK indicator. Student achievement in the Interpretation indicator of 51.58% Analysis 18.75% Evaluation 13.87% Inference 31.48% Explication 14.19% and Self Regulation 26.85%. So KBK students as a whole are in the low category with a percentage of 31.38%. The cause of students 'difficulties in fulfilling CBC indicators is the limited ability of students to formulate and find other alternatives, the completion of students' answers is difficult to draw conclusions and connect substance between materials, and has not been studied in depth so students tend to be careless in solving problems. The solution that can be used is to provide more experience to students in terms of critical thinking skills and additional learning outside school hours.

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Investigation on the tool worn surface morphology and machining characteristics of the Hardox steel using minimum quantity lubrication

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7987 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

L. Mamundi Azaath ◽

U. Natarajan

Keyword(s):

Cubic Boron Nitride ◽

Critical Role ◽

Minimum Quantity Lubrication ◽

Machining Process ◽

Dry Machining ◽

Minimum Quantity ◽

Coated Tool ◽

Tool Surface ◽

Worn Surface ◽

Machining Characteristics

Abstract In recent years, minimum quantity lubrication machining has played a critical role in extending tool life, improving surface finish, and reducing tool wear during the machining of hardened steel. The reported investigation involved the utility of Hardox 500 steel for the machining process while the cubic boron nitride coated tool performed the function of removing the material. The investigation was carried out by adopting two different techniques to predict the responses, viz., the response surface methodology and the artificial neural network. These techniques have been employed to predict the possible responses in investigating machining characteristics. Also, due consideration has been made concerning the reduction of tool-tip temperature and surface roughness. The entire investigation was carried out using three different environments. They are dry machining, wet, and minimum quantity lubrication. A scanning electron microscope was used for examining the morphology of the worn tool surface.

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Investigation on Surface Roughness during Milling of AL-61 Machining under Minimum Quantity Lubrication (MQL)

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.36483 ◽

2021 ◽

Vol 9 (VII) ◽

pp. 1059-1064

Author(s):

Er. Sher Singh

Keyword(s):

Surface Roughness ◽

Tool Life ◽

Surface Finish ◽

Feed Rate ◽

Minimum Quantity Lubrication ◽

Cutting Parameters ◽

Cutting Fluid ◽

Cutting Fluids ◽

Dry Machining ◽

Minimum Quantity

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.

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Influence of Minimum Quantity Lubrication on Friction Coefficient and Work-Material Adhesion During Machining of Cast Aluminum With Various Cutting Tool Substrates Made of Polycrystalline Diamond, High Speed Steel, and Carbides

Journal of Tribology ◽

10.1115/1.4024546 ◽

2013 ◽

Vol 135 (4) ◽

Cited By ~ 16

Author(s):

Pierre Faverjon ◽

Joël Rech ◽

René Leroy

Keyword(s):

Friction Coefficient ◽

Aluminum Alloys ◽

High Speed ◽

Cutting Tool ◽

High Speed Steel ◽

Minimum Quantity Lubrication ◽

Polycrystalline Diamond ◽

Dry Machining ◽

Minimum Quantity ◽

Work Material

Due to the increasing emphasis on environmental constraints, industry works on how to limit the massive use of lubricants by using the micro-pulverization of oil in machining processes and, especially, in the machining of aluminum alloys for the automotive industry. The success of a machining operation is dependent on a friction coefficient and weak adhesion with the tool-work material interface. This paper aims at identifying the influence of cutting tool substrates (high speed steel (HSS), carbide, polycrystalline diamond (PCD)) and of minimum quantity lubrication (MQL) on the friction coefficient and on adhesion in tribological conditions corresponding to the ones observed in the cutting of aluminum alloys (sliding velocity: 20-1500 m/min). An open ball-on-cylinder tribometer, especially designed to simulate these tribological conditions through Hertz contact, has been used. It has been shown that HSS and carbide substrates lead to large friction coefficients (0.8–1) and substantial adhesion in dry conditions, whereas PCD substrates would lead to lower average friction coefficient values (0.4–0.5) and very limited adhesion, which proves the necessity of using PCD tools in the dry machining of aluminum. It has also been shown that the application of MQL leads to a large decrease of the friction coefficient (0.1–0.2) and eliminates almost all traces of adhesions on pins for any substrates, which shows that MQL is an interesting compromise between dry machining and flood cooling.

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