Effect of High-Pressure Coolant Supply on Chip-Breaking and Tool Wear in Machining of Stainless Steel

2015 ◽  
Vol 656-657 ◽  
pp. 226-230 ◽  
Author(s):  
Takahiro Katoh ◽  
Shigetoshi Ohmori ◽  
Takahiro Maeda ◽  
Takanori Kakumitsu ◽  
Koichi Okuda ◽  
...  

The high-pressure coolant supply cutting has attracted attention from a viewpoint of chip evacuation and tool life. In this study, the influence of high-pressure coolant supply on chip shape, cutting force and tool wear were investigated. The tests were carried out during external turning of stainless steel with cemented carbide cutting inserts. The results suggest that the length and radius of the chips got shorter with high-pressure coolant supply, especially supply pressure more than 5MPa. The cutting force was increase slightly with high-pressure coolant supply. However the thrust force was decrease. The uniform flank wear and crater wear were reduced and tool life was improved by high-pressure coolant supply.

2013 ◽  
Vol 554-557 ◽  
pp. 1961-1966 ◽  
Author(s):  
Yessine Ayed ◽  
Guenael Germain ◽  
Amine Ammar ◽  
Benoit Furet

Titanium alloys are known for their excellent mechanical properties, especially at high temperature. But this specificity of titanium alloys can cause high cutting forces as well as a significant release of heat that may entail a rapid wear of the cutting tool. To cope with these problems, research has been taken in several directions. One of these is the development of assistances for machining. In this study, we investigate the high pressure coolant assisted machining of titanium alloy Ti17. High pressure coolant consists of projecting a jet of water between the rake face of the tool and the chip. The efficiency of the process depends on the choice of the operating parameters of machining and the parameters of the water jet such as its pressure and its diameter. The use of this type of assistance improves chip breaking and increases tool life. Indeed, the machining of titanium alloys is generally accompanied by rapid wear of cutting tools, especially in rough machining. The work done focuses on the wear of uncoated tungsten carbide tools during machining of Ti17. Rough and finish machining in conventional and in high pressure coolant assistance conditions were tested. Different techniques were used in order to explain the mechanisms of wear. These tests are accompanied by measurement of cutting forces, surface roughness and tool wear. The Energy-dispersive X-ray spectroscopy (EDS) analysis technique made it possible to draw the distribution maps of alloying elements on the tool rake face. An area of material deposition on the rake face, characterized by a high concentration of titanium, was noticed. The width of this area and the concentration of titanium decreases in proportion with the increasing pressure of the coolant. The study showed that the wear mechanisms with and without high pressure coolant assistance are different. In fact, in the condition of conventional machining, temperature in the cutting zone becomes very high and, with lack of lubrication, the cutting edge deforms plastically and eventually collapses quickly. By contrast, in high pressure coolant assisted machining, this problem disappears and flank wear (VB) is stabilized at high pressure. The sudden rupture of the cutting edge observed under these conditions is due to the propagation of a notch and to the crater wear that appears at high pressure. Moreover, in rough condition, high pressure assistance made it possible to increase tool life by up to 400%.


Author(s):  
Anshuman Das ◽  
Miyaz Kamal ◽  
Sudhansu Ranjan Das ◽  
Saroj Kumar Patel ◽  
Asutosh Panda ◽  
...  

AISI D6 (hardness 65 HRC) is one of the hard-to-cut steel alloys and commonly used in mould and die making industries. In general, CBN and PCBN tools are used for machining hardened steel but its higher cost makes the use for limited applications. However, the usefulness of carbide tool with selective coatings is the best substitute having comparable tool life, and in terms of cost is approximately one-tenth of CBN tool. The present study highlights a detailed analysis on machinability investigation of hardened AISI D6 alloy die steel using newly developed SPPP-AlTiSiN coated carbide tools in finish dry turning operation. In addition, a comparative assessment has been performed based on the effectiveness of cutting tool performance of nanocomposite coating of AlTiN deposited by hyperlox PVD technique and a coating of AlTiSiN deposited by scalable pulsed power plasma (SPPP) technique. The required number of machining trials under varied cutting conditions (speed, depth of cut, feed) were based on L16 orthogonal array design which investigated the crater wear, flank wear, surface roughness, chip morphology, and cutting force in hard turning. Out of the two cutting tools, newly-developed nanocomposite (SPPP-AlTiSiN) coated carbide tool promises an improved surface finish, minimum cutting force, longer tool life due to lower value of crater & flank wears, and considerable improvement in tool life (i.e., by 47.83%). At higher cutting speeds, the crater wear length and flank wear increases whereas the surface roughness, crater wear width and cutting force decreases. Chip morphology confirmed the formation of serrated type saw tooth chips.


2014 ◽  
Vol 800-801 ◽  
pp. 424-429
Author(s):  
Pei Rong Zhang ◽  
Zhan Qiang Liu

The paper investigates the effects of cutting edge preparation on cutting force, cutting temperature and tool wear for hard turning. An optimized characterization approach is proposed and five kinds of cemented tools with different edge preparation are adopted in the simulations by DEFROM-2DTM. The results show that both the forces and cutting temperature on the rake face climb up and then declines with the increasing of factor K (Sγ/Sα). While the temperature on flank face decrease with the increasing of the factor K. When the cutting conditions are identical, flank wear reduces while crater wear exacerbates before easing with the increasing of the factor K. The simulation results will provide valuable suggestions for optimization of cutting edge preparation for hard turning in order to obtain excellent machining quality and longer tool life.


1970 ◽  
Vol 39 (2) ◽  
pp. 71-77 ◽  
Author(s):  
M Kamruzzaman ◽  
NR Dhar

To avoid surface distortion and to improve tool life, machining of alloy steel and other hard materials under high speed-feed condition requires instant heat transfer from the work-tool interface where the intensity of cutting temperature is the maximum. Conventional cooling is completely unable and other special techniques like MQL and cryogenic cooling are not suitable in context of product quality and cost effectiveness. Supply of high-pressure coolant (HPC) with high velocity may provide the best control to reduce cutting temperature and tool wear as well as increase tool life. This paper deals with an experimental investigation on the effect of high-pressure coolant on temperature, tool wear, surface roughness and dimensional deviation in turning 42CrMo4 steel by uncoated carbide inserts and comparing it with dry condition. It is observed that the cutting temperature and tool wear is reduced, tool life is increased, surface finish is improved, and dimensional deviation is decreased with the use of high-pressure coolant. Keywords: High-pressure coolant (HPC), Alloy steel, Temperature, Wear and Product quality. doi:10.3329/jme.v39i2.1849 Journal of Mechanical Engineering, Vol. ME39, No. 2, Dec. 2008 71-77


Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.


2017 ◽  
Vol 882 ◽  
pp. 36-40
Author(s):  
Salah Gariani ◽  
Islam Shyha ◽  
Connor Jackson ◽  
Fawad Inam

This paper details experimental results when turning Ti-6Al-4V using water-miscible vegetable oil-based cutting fluid. The effects of coolant concentration and working conditions on tool flank wear and tool life were evaluated. L27 fractional factorial Taguchi array was employed. Tool wear (VBB) ranged between 28.8 and 110 µm. The study concluded that a combination of VOs based cutting fluid concentration (10%), low cutting speed (58 m/min), feed rate (0.1mm/rev) and depth of cut (0.75mm) is necessary to minimise VBB. Additionally, it is noted that tool wear was significantly affected by cutting speeds. ANOVA results showed that the cutting fluid concentration is statistically insignificant on tool flank wear. A notable increase in tool life (TL) was recorded when a lower cutting speed was used.


2013 ◽  
Vol 690-693 ◽  
pp. 2030-2035
Author(s):  
Shu Bao Yang ◽  
Hong Chao Ni ◽  
Guo Hui Zhu

Ti6Al4V alloy is widely used in the aircraft industry, marine and the commercial applications due to its excellent comprehensive properties. However, its poor machinability prevents it from application widely, and the rapid tool wear is one of the key factors. The FEM models of cutting titanium alloy are established. The effect of tool wear on chip morphology, cutting temperature and cutting force are studied. The simulation results show that: the cutting force and cutting temperature will rise with the increase of tool wear. Furthermore, the degree of chip deformation will improve, but the frequency of serrated chip tooth occurred will decrease.


Sign in / Sign up

Export Citation Format

Share Document