scholarly journals Relationship between surface roughness and chip morphology when turning hardened steel

2020 ◽  
Vol 26 (3) ◽  
pp. 92-98
Author(s):  
Youcef Abidi

AbstractHard machining is a process which has become highly recommended in manufacturing industry to replace grinding and perform production. The important technological parameters that determine this process are tool wear, machined surface roughness, cutting force and morphology of the removed chip. In this work, an attempt has been made to analyse the morphology and form of chip removed during turning of hardened steel AISI 1045 (40HRC) with mixed ceramic tool type CC650. Using a Taguchi plan L9, whose factors are cutting speed and feed rate with three levels for each. Macroscopic and microscopic results of chip morphology were correlated with these two cutting parameters additional to surface roughness. Sufficient experimental results were obtained using the mixed ceramic tool when turning of hardened steel AISI 1045 (40HRC) at high cutting speeds. Roughness of machined surface confirmed that it is influenced by feed rate. Chips show a sawtooth shape for all combinations of the experimental plan used. The chip form changed with cutting parameters variation and given an important indicator of suraface quality for industriel. Having the indicators on the surface quality from simple control of chip without stopping machining give an important advantage in order to maximize production and reduce costs.

2021 ◽  
Author(s):  
Sonia Ezeddini ◽  
Wajdi Rajhi ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar ◽  
Sahbi Ben Salem

Abstract Ti-6242 is a super alloy which exhibits the best creep resistance among available titanium alloys and is widely used in the manufacture by WEDM of aircraft engine turbomachinery components. However, the final quality of wire EDMed surface is a great challenge as it is affected by various factors that need optimization for surface integrity and machine efficiency improvement. The aim of this study is to investigate the effect of a set of cutting process parameters such as pulse on time (Ton), servo voltage (U), feed rate (S) and flushing pressure (p) on surface roughness (SR) when machining Ti-6242 super alloy by WEDM process using a brass tool electrode and deionized water as a dielectric fluid. WEDM experiments were conducted, and SR (Ra) measurement was carried out using a 3D optical surface roughness-meter (3D–SurfaScan). As a tool to optimize cutting parameters for SR improvement, Taguchi's signal‐to‐noise ratio (S/N) approach was applied using L9 (3^4) orthogonal array and Lower-The-Better (LTB) criteria. Substantially, the findings from current investigation suggest the application of the values 0.9 µs, 100V, 29 mm/min, and 60 bar for Ton, U, S and p cutting parameters, respectively, for producing a good surface finish quality. Percent contributions of the machining parameters on SR (Ra) assessed based on ANOVA analysis are 62.94%, 20.84%, 11.46% and 4.74% for U, S, Ton and p, respectively. Subsequently, accurate predictive model for SR (Ra) is established based on response surface analysis (RSA). The contour plots for SR (Ra) indicate that when flushing pressure p converges to a critical value (80 bar), a poor-quality surface finish is highly expected with the excessive increase in U and S. Electron microscope scanning (SEM) observations have been performed on machined surface for a wide range of cutting parameters to characterize wire EDMed surface of Ti-6242. SEM micrographs indicate that the machined surface acquires a foamy structure and shows white layer and machining-induced damage that the characteristics are highly dependent on cutting parameters. At high servo-voltage, the decrease in pulse on time Ton and feed rate S results in a large decrease in overall machining-induced surface damage. Moreover, for high servo-voltage and feed rate levels, it has been observed that pulse on time could play a role of controlling the surface microcracks density. In fact, the use of a low pulse duration of cut combined with high servo-voltage and feed rate has been shown to inhibit surface microcracks formation giving the material surface a better resistance to cracking than at high pulse duration.


2009 ◽  
Vol 407-408 ◽  
pp. 690-693
Author(s):  
Takahiko Kusano ◽  
Ryutaro Tanaka ◽  
Akira Hosokawa ◽  
Takashi Ueda ◽  
Tatsuaki Furumoto ◽  
...  

This study deals with the influence of laser hardening for a carbon steel AISI 1045 on machinability in turning. Turning test was conducted for the purpose to clarify the influence of laser hardening for steel surface on the chip controllability and surface roughness. In turning laser hardened steel, continuous chip is broken in the laser hardened zone during cutting due to higher brittleness. The broken chips have spiral form and their length is approximately equal to those generated by less than 10 revolution cutting. The surface roughness shows slightly lower compared with non-laser hardened steel.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6106
Author(s):  
Waleed Ahmed ◽  
Hussien Hegab ◽  
Atef Mohany ◽  
Hossam Kishawy

It is necessary to improve the machinability of difficult-to-cut materials such as hardened steel, nickel-based alloys, and titanium alloys as these materials offer superior properties such as chemical stability, corrosion resistance, and high strength to weight ratio, making them indispensable for many applications. Machining with self-propelled rotary tools (SPRT) is considered one of the promising techniques used to provide proper tool life even under dry conditions. In this work, an attempt has been performed to analyze, model, and optimize the machining process of AISI 4140 hardened steel using self-propelled rotary tools. Experimental analysis has been offered to (a) compare the fixed and rotary tools performance and (b) study the effect of the inclination angle on the surface quality and tool wear. Moreover, the current study implemented some artificial intelligence-based approaches (i.e., genetic programming and NSGA-II) to model and optimize the machining process of AISI 4140 hardened steel with self-propelled rotary tools. The feed rate, cutting velocity, and inclination angle were the selected design variables, while the tool wear, surface roughness, and material removal rate (MRR) were the studied outputs. The optimal surface roughness was obtained at a cutting speed of 240 m/min, an inclination angle of 20°, and a feed rate of 0.1 mm/rev. In addition, the minimum flank tool wear was observed at a cutting speed of 70 m/min, an inclination angle of 10°, and a feed rate of 0.15 mm/rev. Moreover, different weights have been assigned for the three studied outputs to offer different optimized solutions based on the designer’s interest (equal-weighted, finishing, and productivity scenarios). It should be stated that the findings of the current work offer valuable recommendations to select the optimized cutting conditions when machining hardened steel AISI 4140 within the selected ranges.


2018 ◽  
Vol 779 ◽  
pp. 153-158
Author(s):  
Phacharadit Paengchit ◽  
Charnnarong Saikaew

This work investigated the influences of cutting speed and feed rate on surface roughness in hard turning of AISI 4140 chromium molybdenum steel bar using mixed ceramic inserts Al2O3+TiC under dry condition for automotive industry applications. Turning experiments were conducted by varying cutting speed ranging from 150 to 220 m/min and feed rate ranging from 0.06 to 1 mm/rev. General factorial design was used to analyze the data set of surface roughness and determine statistically significant process factors based on analysis of variance results. The results showed that average surface roughness was significantly affected by feed rate and interaction between cutting speed and feed rate at the level of significance of 0.05. An optimal operating condition for hard turning of AISI 4140 with the ceramic cutting tool that produced a minimum machined surface roughness was obtained at cutting speed of 220 m/min and 0.06 mm/rev.


2010 ◽  
Vol 136 ◽  
pp. 86-90 ◽  
Author(s):  
Wei Zhang ◽  
Min Li Zheng ◽  
Ming Ming Cheng ◽  
Quan Wan

By using experiment cutter edge topography obtained by super depth three-dimension microscope, fits the cutter edge curve and calculate experiment cutter edge radius value; by high speed milling hardened steel experiment, individually researches cutter edge and cutting parameters influence on machined surface in high speed milling hardened steel with end-milling cutter and ball-end milling cutter. The experiment analysis results show that under the same cutting parameters condition, machined surface roughness in high speed end-milling cutter milling is better than in high speed ball-end milling; within experiment selected cutting parameter range, cutter edge radius is the main influence factor on machined surface roughness in high speed end- milling hardened steel, while the influence on machined surface roughness in high speed ball-end milling hardened steel is not obvious. In end-milling, when edge radius and milling depth are in the same order magnitude or the difference is not obvious, milling depth should be a little bigger than selected cutter edge radius value.


2013 ◽  
Vol 670 ◽  
pp. 70-75 ◽  
Author(s):  
Wei Zhang ◽  
M.L. Zheng ◽  
M.M. Cheng ◽  
W.T. Wang

By using experiment cutter edge topography obtained by super depth three-dimension microscope, fits the cutter edge curve and calculate experiment cutter edge radius value; by high speed milling hardened steel experiment, individually researches cutter edge and cutting parameters influence on machined surface in high speed milling hardened steel with end-milling cutter and ball-end milling cutter. The experiment analysis results show that under the same cutting parameters condition, machined surface roughness in high speed end-milling cutter milling is better than in high speed ball-end milling; within experiment selected cutting parameter range, cutter edge radius is the main influence factor on machined surface roughness in high speed end- milling hardened steel, while the influence on machined surface roughness in high speed ball-end milling hardened steel is not obvious. In end-milling, when edge radius and milling depth are in the same order magnitude or the difference is not obvious, milling depth should be a little bigger than selected cutter edge radius value.


2015 ◽  
Vol 13 ◽  
pp. 19-22 ◽  
Author(s):  
Gabriel Benga ◽  
Danut Savu ◽  
Adrian Olei

The paper presents the influence of various cutting regimes on the surface roughness, when a hardened bearing steel has been machined using both ceramic and PCBN cutting tools. There were used different cutting conditions varying cutting speed, feed rate and depth of cut in order to determine the influence of each cutting parameter on the surface finish.


2016 ◽  
Vol 835 ◽  
pp. 236-241
Author(s):  
P.Y.M. Wibowo Ndaruhadi ◽  
Bambang Santosa

Drilling process has many applications including making molds and dies, all requires different quality of the drilled hole. The aim of this study is to establish models and optimization of cutting parameter to get the best hole quality, including enlargement diameter, circularity error and surface roughness in drilling hardened steel. Drilling experiments have been performed using different cutting parameters (i.e. cutting speed and feed rate) and employ and uncoated carbide drill under flooded cooling. The experimental results show that both of the cutting speed and feed rate significantly affect all responses. Models for responses have been developed for investigation in this study, and their optimizations have been obtained, showing better quality of the drilled hole produced at higher cutting speed and lower feed rate. Desirability for the optimum criteria is 0.944 at the highest cutting speed (60 m/min) and lowest feed rate (0.05 mm/rev).


Sign in / Sign up

Export Citation Format

Share Document