scholarly journals Modelling Surface Roughness in the Function of Torque When Drilling

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 337
Author(s):  
Zdravko Krivokapić ◽  
Radoslav Vučurević ◽  
Davorin Kramar ◽  
Jelena Šaković Jovanović

Given the application of a multiple regression and artificial neural networks (ANNs), this paper describes development of models for predicting surface roughness, linking an arithmetic mean deviation of a surface roughness to a torque as an input variable, in the process of drilling enhancement steel EN 42CrMo4, thermally treated to the hardness level of 28 HRC, using cruciform blade twist drills made of high speed steel with hardness level of 64–68 HRC. The model was developed using process parameters (nominal diameters of twist drills, speed, feed, and angle of installation of work pieces) as input variables varied at three levels by Taguchi design of experiment and measured experimental data for a torque and arithmetic mean deviation of a surface roughness for different values of flank wear of twist drills. The comparative analysis of the models results and the experimental data, acquired for the inputs at the moment when a wear span reaches a limit value corresponding to a moment of the drills blunting, demonstrates that the neural network model gives better results than the results obtained in the application of multiple linear and nonlinear regression models.

2021 ◽  
Author(s):  
Zdravko Krivokapić ◽  
Radoslav Vučurević ◽  
Predrag V. Dasic ◽  
Petar Ivanković

Abstract This paper presents a model of dependence between the parameters of surface roughness and the parameters of cylindricity and eccentricity in drilling operation for the enhancing steel EN 42CrMo4, hardness 28 HRC, with twist drills DIN 338 made of high-speed steel EN HS6-5-2, with normal blade. The quality of machining, besides the accuracy of measures, completely determined with the values of the parameters of the surface roughness and the parameters of form and location, hence this paper is oriented to the creating models between parameters of the quality of a machined surface and parameters of deviations from form and position. By the developing models based on artificial neural networks and using experimental results, it is possible to analyse the quality of machining on the basis of parameters of a surface roughness.


Author(s):  
Adem Çiçek ◽  
Ilyas Uygur ◽  
Turgay Kıvak ◽  
Nursel Altan Özbek

In this paper, machinability of AISI 316 austenitic stainless steel was investigated using cryogenically treated and untreated high-speed steel (HSS) twist drills. Machinability of AISI 316 austenitic stainless steel was evaluated in terms of thrust force, tool life, surface roughness, and hole quality of the drilled holes. Experimental results showed from 14% to 218% improvements for treated tool lives. Thrust force, surface roughness, and hole quality are better with treated drills when compared with untreated drills. These improvements were mainly attributed to formation of fine and homogeneous carbide particles and transformation of retained austenite to martensite. Microhardness and microstructure observations verified these formations.


2019 ◽  
Vol 14 (2) ◽  
pp. 14-21
Author(s):  
Aseel Jameel Haleel

This paper focuses on the optimization of drilling parameters by utilizing “Taguchi method” to obtain the minimum surface roughness. Nine drilling experiments were performed on Al 5050 alloy using high speed steel twist drills. Three drilling parameters (feed rates, cutting speeds, and cutting tools) were used as control factors, and L9 (33) “orthogonal array” was specified for the experimental trials. Signal to Noise (S/N) Ratio and “Analysis of Variance” (ANOVA) were utilized to set the optimum control factors which minimized the surface roughness. The results were tested with the aid of statistical software package MINITAB-17. After the experimental trails, the tool diameter was found as the most important factor that has effect on the surface roughness. The optimal drilling factors that minimized the surface roughness are (20mm/min cutting speed, 0.2 mm/rev feed rate, and 10mm tool diameter).


2020 ◽  
Vol 38 (9A) ◽  
pp. 1352-1358
Author(s):  
Saad K. Shather ◽  
Abbas A. Ibrahim ◽  
Zainab H. Mohsein ◽  
Omar H. Hassoon

Discharge Machining is a non-traditional machining technique and usually applied for hard metals and complex shapes that difficult to machining in the traditional cutting process. This process depends on different parameters that can affect the material removal rate and surface roughness. The electrode material is one of the important parameters in Electro –Discharge Machining (EDM). In this paper, the experimental work carried out by using a composite material electrode and the workpiece material from a high-speed steel plate. The cutting conditions: current (10 Amps, 12 Amps, 14 Amps), pulse on time (100 µs, 150 µs, 200 µs), pulse off time 25 µs, casting technique has been carried out to prepare the composite electrodes copper-sliver. The experimental results showed that Copper-Sliver (weight ratio70:30) gives better results than commonly electrode copper, Material Removal Rate (MRR) Copper-Sliver composite electrode reach to 0.225 gm/min higher than the pure Copper electrode. The lower value of the tool wear rate achieved with the composite electrode is 0.0001 gm/min. The surface roughness of the workpiece improved with a composite electrode compared with the pure electrode.


Alloy Digest ◽  
1987 ◽  
Vol 36 (10) ◽  

Abstract AISI Type M7 is a molybdenum type of high-speed steel. It is somewhat similar to AISI Type M1 tool steel but with higher percentages of carbon and vanadium to provide an improvement over AISI Type M1 in cutting characteristics without a significant loss in toughness. It is suitable for a wide variety of cutting-tool applications where improved resistance to abrasion is required. The many uses of Type M7 include twist drills, end mills, shear blades, punches, milling cutters, lathe tools, taps and reamers. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-483. Producer or source: Tool steel mills. See also Alloy Digest TS-468, January 1987.


Alloy Digest ◽  
2006 ◽  
Vol 55 (9) ◽  

Abstract Tatmo is a general-purpose high-speed steel often used in twist drills and taps. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on wear resistance as well as forming, heat treating, and machining. Filing Code: TS-633. Producer or source: Timken Latrobe Steel.


Alloy Digest ◽  
2019 ◽  
Vol 68 (9) ◽  

Abstract Böhler (or Boehler) S705 is a cobalt alloyed, tungsten-molybdenum high-speed steel. Applications include turning and planing tools of all types, milling cutters,taps, twist drills, woodworking tools, and cold work tools. See also Alloy Digest TS-761, April 2019. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on heat treating and machining. Filing Code: TS-776. Producer or source: Voestalpine BÖHLER Edelstahl GmbH & Co KG.


2015 ◽  
Vol 67 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Mumin Sahin ◽  
Cenk Misirli ◽  
Dervis Özkan

Purpose – The purpose of this paper is to examine mechanical and metallurgical properties of AlTiN- and TiN-coates high-speed steel (HSS) materials in detail. Design/methodology/approach – In this study, HSS steel parts have been processed through machining and have been coated with AlTiN and TiN on physical vapour deposition workbench at approximately 6,500°C for 4 hours. Tensile strength, fatigue strength, hardness tests for AlTiN- and TiN-coated HSS samples have been performed; moreover, energy dispersive X-ray spectroscopy and X-ray diffraction analysis and microstructure analysis have been made by scanning electron microscopy. The obtained results have been compared with uncoated HSS components. Findings – It was found that tensile strength of TiAlN- and TiN-coated HSS parts is higher than that of uncoated HSS parts. Highest tensile strength has been obtained from TiN-coated HSS parts. Number of cycles for failure of TiAlN- and TiN-coated HSS parts is higher than that for HSS parts. Particularly TiN-coated HSS parts have the most valuable fatigue results. However, surface roughness of fatigue samples may cause notch effect. For this reason, surface roughness of coated HSS parts is compared with that of uncoated ones. While the average surface roughness (Ra) of the uncoated samples was in the range of 0.40 μm, that of the AlTiN- and TiN-coated samples was in the range of 0.60 and 0.80 μm, respectively. Research limitations/implications – It would be interesting to search different coatings for cutting tools. It could be the good idea for future work to concentrate on wear properties of tool materials. Practical implications – The detailed mechanical and metallurgical results can be used to assess the AlTiN and TiN coating applications in HSS materials. Originality/value – This paper provides information on mechanical and metallurgical behaviour of AlTiN- and TiN-coated HSS materials and offers practical help for researchers and scientists working in the coating area.


2019 ◽  
Vol 130 ◽  
pp. 01031 ◽  
Author(s):  
The Jaya Suteja ◽  
Yon Haryono ◽  
Andri Harianto ◽  
Esti Rinawiyanti

Polyacetal is commonly used as bushing material because of its low coefficient of friction and self lubricant characteristics. The polyacetal is machined by using boring process to produce bushing in certain surface roughness. The objectives of this research are to optimize three independent parameters (depth of cut, feed rate and principal cutting edge angle) of boring process of polyacetal using high speed steel tool to achieve the highest material removal rate and the required surface roughness. Response Surface Methodology is used to investigate the influence of the parameters and optimize the boring process. The research shows that the influence of the boring process parameters on polyacetal is similar compared to on metal. The result reveals that the optimum result is achieved by applying the value of depth of cut, feed rate, and principal cutting edge angle is 2.9 × 10–3 m, 0.229 mm rev–1, and 99.1° respectively. By applying these values, the maximum material rate removal achieved in this research is 1263.4 mm3 s–1 and the surface roughness achieved is 1.57 × 10–6 m.


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