scholarly journals On the Effect of Multiple Passes on Kerf Characteristics and Efficiency of Abrasive Waterjet Cutting

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 74
Author(s):  
Panagiotis Karmiris-Obratański ◽  
Nikolaos E. Karkalos ◽  
Rafał Kudelski ◽  
Emmanouil L. Papazoglou ◽  
Angelos P. Markopoulos

Abrasive waterjet cutting is a well-established non-conventional technique for the processing of difficult-to-cut material and rendering of various complex geometries with high accuracy. However, as in every machining process, it is also required that high efficiency and productivity are achieved. For that reason, in the present study, the effect of performing the machining process by multiple passes is investigated, and the evaluation of this approach is performed in terms of total depth of penetration, kerf width, kerf taper angle, mean material removal rate, and cutting efficiency. In the case of multiple passes, the passes are performed in the same direction with the traverse speed adjusted accordingly in order to maintain the total machining time constant in each case. From the experimental results, it was found that the effect of multiple passes on the kerf characteristics, mean material removal rate, and cutting efficiency depends on the process conditions, especially regarding the depth of penetration, and it is possible to achieve significantly higher efficiency by the multi-pass cutting technique when the appropriate process conditions are selected.

2016 ◽  
Vol 10 (3) ◽  
pp. 392-400 ◽  
Author(s):  
M. Ramulu ◽  
◽  
Vara Isvilanonda ◽  
Rishi Pahuja ◽  
Mohamed Hashish ◽  
...  

High temperature Fiber Metal Laminate – Titanium/Graphite (Ti/Gr) is an advanced material system, developed to meet the high temperature requirements in aerospace applications. High specific strength and stiffness of composite core along with its protection from aggressive environment by tough titanium alloy sheets qualify FMLs for a promising alternative material where metallic and composites overcome each other's limitations. However, industrial employability of this three phase system is often limited by the machining challenges posed by the difference in material removal mechanisms of Titanium alloy, PIXA thermoplastic polyimide resin and graphite fibers. An experimental investigation was conducted to evaluate the machinability of 1 mm thick Ti/Gr laminate sheets through Abrasive Waterjet (AWJ) machining process in terms of kerf characteristics and material removal rate. The parametric influence of AWJ operating variables on machining performance was studied by systematically measuring operating variables (traverse speed and Abrasive flow rate) using fully crossed Design of experiment (DOE) scheme, and statistically analyzing using ANOVA (Analysis of variance) technique. Empirical models were developed to quantify these effects and predict the influence of process parameters on material removal rate, kerf taper, entry damage width and overcut in straight cutting of Ti/Gr sheets.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Prasad D. Unde ◽  
M. D. Gayakwad ◽  
N. G. Patil ◽  
R. S. Pawade ◽  
D. G. Thakur ◽  
...  

Abrasive waterjet machining (AWJM) is an emerging machining process in which the material removal takes place due to abrasion. A stream of abrasive particles mixed with filtered water is subjected to the work surface with high velocity. The present study is focused on the experimental research and evaluation of the abrasive waterjet machining process in order to evaluate the technological factors affecting the machining quality of CFRP laminate using response surface methodology. The standoff distance, feed rate, and jet pressure were found to affect kerf taper, delamination, material removal rate, and surface roughness. The material related parameter, orientation of fiber, has been also found to affect the machining performance. The kerf taper was found to be 0.029 for 45° fiber orientation whereas it was 0.036 and 0.038 for 60° and 90°, respectively. The material removal rate is 18.95 mm3/sec for 45° fiber orientation compared to 18.26 mm3/sec for 60° and 17.4 mm3/sec for 90° fiber orientation. The Ra value for 45° fiber orientation is 4.911 µm and for 60° and 90° fiber orientation it is 4.927 µm and 4.974 µm, respectively. Delamination factor is found to be more for 45° fiber orientation, that is, 2.238, but for 60° and 90° it is 2.029 and 2.196, respectively.


2021 ◽  
Vol 11 (11) ◽  
pp. 4925
Author(s):  
Jennifer Milaor Llanto ◽  
Majid Tolouei-Rad ◽  
Ana Vafadar ◽  
Muhammad Aamir

Abrasive water jet machining is a proficient alternative for cutting difficult-to-machine materials with complex geometries, such as austenitic stainless steel 304L (AISI304L). However, due to differences in machining responses for varied material conditions, the abrasive waterjet machining experiences challenges including kerf geometric inaccuracy and low material removal rate. In this study, an abrasive waterjet machining is employed to perform contour cutting of different profiles to investigate the impacts of traverse speed and material thickness in achieving lower kerf taper angle and higher material removal rate. Based on experimental investigation, a trend of decreasing the level of traverse speed and material thickness that results in minimum kerf taper angle values of 0.825° for machining curvature profile and 0.916° for line profiles has been observed. In addition, higher traverse speed and material thickness achieved higher material removal rate in cutting different curvature radii and lengths in line profiles with obtained values of 769.50 mm3/min and 751.5 mm3/min, accordingly. The analysis of variance revealed that material thickness had a significant impact on kerf taper angle and material removal rate, contributing within the range of 69–91% and 62–69%, respectively. In contrast, traverse speed was the least factor measuring within the range of 5–18% for kerf taper angle and 27–36% for material removal rate.


Author(s):  
Sundar Marimuthu ◽  
Bethan Smith

This manuscript discusses the experimental results on 300 W picosecond laser machining of aerospace-grade nickel superalloy. The effect of the laser’s energetic and beam scanning parameters on the machining performance has been studied in detail. The machining performance has been investigated in terms of surface roughness, sub-surface thermal damage, and material removal rate. At optimal process conditions, a picosecond laser with an average power output of 300 W can be used to achieve a material removal rate (MRR) of ∼140 mm3/min, with thermal damage less than 20 µm. Shorter laser pulse widths increase the material removal rate and reduce the resultant surface roughness. High scanning speeds improve the picosecond laser machining performance. Edge wall taper of ∼10° was observed over all the picosecond laser machined slots. The investigation demonstrates that high-power picosecond lasers can be used for the macro-machining of industrial components at an acceptable speed and quality.


Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.


2017 ◽  
Vol 107 (09) ◽  
pp. 674-680
Author(s):  
E. Prof. Abele ◽  
C. Hasenfratz ◽  
C. Praetzas ◽  
G. M. Schüler ◽  
C. Stark ◽  
...  

Die Herstellung von Verdichterscheiben stellt hohe Ansprüche an die Fertigungstechnik. Neue, schwer zu zerspanende Materialien und Integralkonstruktionen erzeugen eine hohe Komplexität bei der Ausführung. Das Projekt „SchwerSpan“ stellt sich dieser Herausforderung und entwickelt einen Prozess zur Schruppfräsbearbeitung von Verdichterscheiben. Ziel des Projekts ist eine Reduktion der Werkzeugkosten bei erhöhtem Zeitspanvolumen.   The production of compressor disks places high demands on the manufacturing technology. A very complex task is created by new difficult-to-cut materials and integral components. The project “SchwerSpan” is taking on this task by developing a machining process for rough milling in the production of compressor disks. The aim of the process is to reduce the tool costs by increasing material removal rate.


2019 ◽  
Vol 54 (13) ◽  
pp. 1741-1759 ◽  
Author(s):  
Dhiraj Kumar ◽  
Suhasini Gururaja

In present work, abrasive waterjet machining has been used to machine adhesively bonded titanium-carbon fiber-reinforced plastics-titanium hybrid laminate with varying traverse speed, jet pressure, and stand-off distance. The effect of varying abrasive waterjet machining parameters on cut quality has been quantified by material removal rate, metal composite interface damage factor, taper ratio ( T r), and surface roughness (Ra). Response surface methodology along with central composite design has been used to analyze the influence of process parameters on output responses. Additionally, analysis of variance was performed to identify the significant parameters on the output responses. For better abrasive waterjet cut quality, the optimal values of process parameters obtained were 200 MPa jet pressure, 237.693 mm/min traverse speed, and 1 mm stand-off distance. The corresponding material removal rate, metal composite interface damage factor, taper ratio, and surface roughness are 5.388 mm3/s, 1.41, 1.16, and 3.827 µm, respectively. Furthermore, validation tests have been performed with obtained optimal parameters that deliver satisfactory outcomes with an error of 5.35%, 3.07%, 2.29%, and 0.39% for material removal rate, metal composite interface damage factor, taper ratio, and surface roughness, respectively.


2019 ◽  
Vol 814 ◽  
pp. 127-131
Author(s):  
Patittar Nakwong ◽  
Apiwat Muttamara

Wire electrical discharge machine (WEDM) is non-conventional machining process. It can be used for hard cutting material. The study has been presented the combining WEDM with an ultrasonic machine (USM) with brass and tungsten were used as a wire electrode and workpiece respectively. The experiment was carried out with an ultrasonic transducer at 40, 80 kHz. The results were observed with the material removal rate (MRR) and surface roughness (Ra). This research introduced the method of USM setup and described the effected of vibration with the wire electrode on the displacement of amplitude. The result shows that the WEDM process with USM at 40 kHz can be more improved with the material removal rate and surface roughness than that of USM at 80 kHz. This can be explained that higher frequency affected to vibration displacement which makes lower amplitude.


Author(s):  
Pankaj Kumar Shrivastava ◽  
Avanish Kumar Dubey

Metal matrix composites (MMCs) have wide applications in modern manufacturing industries due to their specific and improved technological characteristics such as high strength to weight ratio, high hardness, high thermal, corrosion and wear resistances. Such characteristics are highly demanded in automobile, aircraft and space research organizations. Shaping of MMCs has been a big challenge for manufacturing industries due to their superior mechanical properties and the peculiar microstructure composed of different phases in MMCs poses machining challenges. Unconventional machining methods have become an alternative to give desired shapes with intricate profiles and stringent design requirements. The aim of present research is to investigate the machining performance of copper-iron-carbide MMC using hybrid machining process, electric discharge diamond grinding (EDDG). A hybrid approach of neural network and genetic algorithm has been used to develop the intelligent model for material removal rate (MRR) and subsequent optimization with the experimental data obtained by scientifically designed experimentation.


Author(s):  
Zhongde Shi ◽  
Amr Elfizy ◽  
Helmi Attia ◽  
Gilbert Ouellet

This paper reports an experimental study on grinding of chromium carbide coatings using electroplated diamond wheels. The work was motivated by machining carbide coatings in gas turbine engine applications. The objective is to explore the process conditions and parameters satisfying the ground surface quality requirements. Surface grinding experiments were conducted with water-based grinding fluid on chromium carbide coated on flat surfaces of aluminum blocks for rough grinding at a fixed wheel speed vs = 30 m/s, and finish grinding at vs = 30, 60 m/s. The effects of depth of cut and workspeed on grinding power, forces, and surface roughness were investigated for each of the wheel speeds. Material removal rate Q = 20 mm3/s for rough grinding at a grinding width b = 101.6 mm was achieved. It was found that the maximum material removal rate achievable in rough grinding was restricted by chatters, which was mainly due to the large grinding width. The specific energy ranged from 27 to 59 J/mm3 under the tested conditions. Surface roughness Ra = 3.5–3.8 μm were obtained for rough grinding, while Ra = 0.6–1.5 μm were achieved for finish grinding. Surface roughness was not sensitive to grinding parameters under the tested conditions, but was strongly dependent on the diamond grain sizes. Imposing axial wheel oscillations to the grinding motions reduced surface roughness by about 60% under the tested condition. It was proved that it is feasible to grind the chromium carbide coating with electroplated diamond wheels.


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