Influence of cutting condition on chip morphology when turning hardened stainless steel using coated carbide cutting tools under minimum quantity of lubrication

2020 ◽  
Author(s):  
Mohamed Handawi Saad Elmunafi ◽  
M. Y. Noordin ◽  
Amad Elddein Elshwain ◽  
D. Kurniawan
2019 ◽  
Vol 11 (8) ◽  
pp. 168781401987089 ◽  
Author(s):  
Yingshuai Xu ◽  
Zhihui Wan ◽  
Ping Zou ◽  
Qinjian Zhang

There are many problems and physical phenomena in turning process, like machined surface quality, cutting force, tool wear, and so on. These factors and the chip shape of workpiece materials, which is an important aspect to study the mechanism of ultrasonic vibration–assisted turning, go hand in hand. This article first introduces the types and changes of chip, meanwhile the chip formation mechanism of ultrasonic vibration–assisted turning is studied and analyzed, and the turning experiments of 304 austenitic stainless steel with and without ultrasonic vibration are carried out. The difference of chip morphology between ultrasonic vibration–assisted turning and conventional turning is contrasted and analyzed from the macroscopic and microscopic point of view. The influence of process parameters on chip shape and the impact of chip shape on machining effect are also analyzed. Results indicate that when process parameters (vibration frequency, ultrasonic amplitude, and cutting parameters) are suitably selected, ultrasonic vibration–assisted turning can gain access to better chip shape and chip breaking effect than conventional turning. By contrast with conventional turning, phenomenon of serrated burr on the chip edge and the surface defects of chip in ultrasonic vibration–assisted turning have improved significantly. Moreover, it is found that superior chip morphology in ultrasonic vibration–assisted turning can be acquired under the circumstance of comparatively small cutting parameters (cutting speed, depth of cut, and feed rate); at the same time, preferable chips can also obtain ranking machining effect.


2012 ◽  
Vol 499 ◽  
pp. 348-352 ◽  
Author(s):  
Xiao Li Zhu ◽  
Song Zhang ◽  
X.L. Xu ◽  
H.G. Lv

In the present study, an experimental investigation has been carried out in an attempt to monitor tool wear progress in turning Inconel 718 with coated carbide inserts under the wet cutting condition. First, each experimental test was conducted with a new cutting edge and the turning process was stopped at a certain interval of time. Secondly, the indexable insert was removed from the tool holder and the flank wear of the insert was measured using a three-dimensional digital microscopy (VHX-600E); and then the insert was clamped into the tool holder for the next turning experiment. The final failure of tool wear surfaces were examined under a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). It is indicated that significant flank wear was the predominant failure mode, and the abrasive, adhesive and oxidation wear were the most dominant wear mechanisms which directly control the deterioration and final failure of the cutting tools.


Author(s):  
Emel Kuram

Tool coatings can improve the machinability performance of difficult-to-cut materials such as titanium alloys. Therefore, in the current work, high-speed milling of Ti6Al4V titanium alloy was carried out to determine the performance of various coated cutting tools. Five types of coated carbide inserts – monolayer TiCN, AlTiN, TiAlN and two layers TiCN + TiN and AlTiN + TiN, which were deposited by physical vapour deposition – were employed in the experiments. Tool wear, cutting force, surface roughness and chip morphology were evaluated and compared for different coated tools. To understand the tool wear modes and mechanisms, detailed scanning electron microscope analysis combined with energy dispersive X-ray of the worn inserts were conducted. Abrasion, adhesion, chipping and mechanical crack on flank face and coating delamination, adhesion and crater wear on rake face were observed during high-speed milling of Ti6Al4V titanium alloy. In terms of tool wear, the lowest value was obtained with TiCN-coated insert. It was also found that at the beginning of the machining pass TiAlN-coated insert and at the end of machining TiCN-coated insert gave the lowest cutting force and surface roughness values. No change in chip morphology was observed with different coated inserts.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2799
Author(s):  
Mohammad Shariful Islam Chowdhury ◽  
Bipasha Bose ◽  
German Fox-Rabinovich ◽  
Stephen Clarence Veldhuis

The machining of Ti6Al4V alloy, especially at low cutting speeds, is associated with strong Built-Up Edge (BUE) formation. The PVD coatings applied on cutting tools to machine such materials must have the necessary combination of properties to address such an underlying wear mechanism. The present work investigates and shows that TiB2 PVD coating can be designed to have certain mechanical properties and tribological characteristics that improve machining in cases where BUE formation is observed. Three TiB2 coatings were studied: one low hardness coating and two high hardness coatings with varied coating thicknesses. Wear performances for the various TiB2 coated carbide tools were evaluated while rough turning Ti6Al4V. Tool wear characteristics were evaluated using tool life studies and the 3D wear volume measurements of the worn surface. Chip morphology analyses were done to assess the in-situ tribological performance of the coatings. The micro-mechanical properties of the coatings were also studied in detail to co-relate with the coatings’ performances. The results obtained show that during the rough turning of Ti6Al4V alloy with intensive BUE formation, the harder TiB2 coatings performed worse, with coating delamination on the rake surface under operation, whereas the softer version of the coating exhibited significantly better tool life without significant coating failure.


Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1931
Author(s):  
Anshuman Das ◽  
Smita Padhan ◽  
Sudhansu Ranjan Das ◽  
Mohammad S. Alsoufi ◽  
Ahmed Mohamed Mahmoud Ibrahim ◽  
...  

Sustainable manufacturing has received great attention in the last few decades for obtaining high quality products with minimal costs and minimal negative impacts on environment. Sustainable machining is one of the main sustainable manufacturing branches, which is concerned with improving environmental conditions, reducing power consumption, and minimizing machining costs. In the current study, the performance of three sustainable machining techniques, namely dry, compressed air cooling, and minimum quantity lubrication, is compared with conventional flood machining during the turning of austenitic stainless steel (Nitronic 60). This alloy is widely used in aerospace engine components, medical applications, gas power industries, and nuclear power systems due to its superior mechanical and thermal properties. Machining was performed using SiAlON ceramic tool with four different cutting speeds, feeds and a constant depth of cut. Consequently, various chip characteristics such as chip morphology, chip thickness, saw tooth distance and chip segmentation frequency were analyzed with both optical and scanning electron microscopes. Performance assessment was performed under the investigated cutting conditions. Our results show that the tool life under MQL machining are 138%, 72%, and 11% greater than dry, compressed air, and flooded conditions, respectively. The use of SiAlON ceramic tool results is more economically viable under the MQL environment as the overall machining cost per component is lower ($0.27) as compared to dry ($0.36), compressed air ($0.31), and flooded ($0.29) machining conditions. The minimum quantity lubrication technique outperformed the other investigated techniques in terms of eco-friendly aspects, economic feasibility, and technical viability to improve sustainability.


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