Nevertheless, the side effects induced by current composite grinding methods, such as temperature gradient and chatter marks, tend to be more obvious in the micromachining process. Atmospheric pressure plasma jet (APPJ) can effectively improve metal …
Rowe, W.B. High-Speed Grinding. Princ. Mod. Grind. Technol. 2014, 101–112. [Google Scholar] Fritsche, A.; Bleicher, F. Analysis of the thermal impact on gamma titanium aluminide by grinding with internal coolant supply based on experimental investigation and transient thermal simulation. Procedia CIRP 2015, 31, 154–159.
A nozzle assembly and method is configured to apply coherent jets of coolant in a tangential direction to the grinding wheel in a grinding process, at a desired temperature, pressure and flowrate, to minimize thermal damage in the part being ground. Embodiments of the present invention may be useful when grinding thermally sensitive materials such as gas turbine creep resistant alloys and ...
Thus, high pressure draft is an efficient low-carbon processing technology. However, studies show that cooling effect of high pressure draft is too limited to meet the needs of strengthened high-temperature heat transfer of the grinding zone [8 –12]. The processing quality of the workpiece and the grinding wheel life is worse than the ...
Effects of a high-pressure coolant jet on machining ... to control this high grinding zone temperature, but all have their shortfalls, both technological and environmental, in exchange for ...
In this technology, coolant is carried by high-pressure cryogenic air (–20°C) and reaches the machining form of mist jet to enhance heat transfer in machining zone. This paper mainly cooling effects of CPMJI in surface grinding, compared with grinding with compressed flood cooling. CPMJI seems to have better effects than other cooling methods.
Eda et al. [9] used the jet infusion technique of delivering the coolant as a high pressure jet, which reduced the temperature, but only with a high percentage of extreme pressure additives. Howes [10] suggested that in grinding, lubrication is much more important than cooling as it reduces the amount of heat generation by reducing the specific ...
The present work investigates the role of high-pressure coolant jet on chip formation, grinding zone temperature and surface roughness in grinding AISI-1040 steel.
In the case of CAMQL with air jet of 0.4 MPa pressure and 14 °C temperature due to its better cooling effect, surface quality is better than that of dry and is close to fluid surface quality. Therefore, besides eliminating cutting fluids the range of application of MQL in grinding of soft steel is developed by using vortex tube.
The Joule-Thomson Effect describes the change in temperature of a gas as it experiences a rapid change in pressure from passing through a valve, orifice or nozzle. It may represent a safety hazard, or an opportunity depending on the process.
The experimental results show that high-pressure water jet impinging has remarkable cooling effect. The temperature of the workpiece surface can be steadily kept below 100°C, while the workpiece ...
[6] S. Paul, A.B. Chattopadhyay: Effects of cryogenic cooling by liquid nitrogen jet on forces, temperature and surface residual stresses in grinding steels, Cryogenics Vol. 35 (1995). [7] S. Shaji, V. Radhakrishnan: An investigation on surface grinding using graphite as lubricant, International Journal of Machine Tools & Manufacture, Vol. 42 ...
The result obtained from this experiment shows 20% reduction in average chip-tool interface temperature and 5% to 20%.reduction in cutting forces.Kamruzzaman M. et al. [8] experimentally investigated the effects of High-Pressure Coolant (HPC) jet in machining of 42Crmo4 steel by uncoated carbide inserts.
In this paper, a new high efficiency cooling technology based on GM is proposed, called as CPMJ. In this technology, a little quantity of 0 °C water is carried by high pressure cryogenic air (–20 °C) and reaches the grinding zone in the form of high speed mist jet to enhance heat transfer and gain the best cooling effect.
Fluid application in grinding is getting attention as higher stock removal rates, higher surface integrity and longer wheel life are required. It is necessary to define proper conditions of application for meeting high productivity goals by lowering the specific grinding energy and reducing the temperature of the contact zone. The present study investigated the capacity of the jet pressure of ...
causes bad effects on both the wheel and workpiece. A number of attempts have been made in the past to control high localized temperature inside the grinding zone. They include the application of conventional flood cooling, Z-Z method of cooling, mist cooling, jet cooling, etc. [2,3,5]. Although, profuse, flood cooling with
Clinical neurosurgeons used micro grinding to remove bone tissues, and drip irrigation-type normal saline (NS) is used with low cooling efficiency. Osteonecrosis and irreversible thermal neural injury caused by excessively high grinding temperature are bottleneck problems in neurosurgery and have severely restricted the application of micro grinding in surgical procedures. Therefore, a ...
The experimental results show that high-pressure jet impingement has remarkable cooling effect. The temperature of the workpiece surface can be steadily kept below the critical film boiling ...
However, high-pressure coolant (HPC) jet effectively reduces cutting zone temperature entering into chip tool interface maintaining a good surface integrity. The present work investigates the role of high-pressure coolant jet on chip formation, grinding zone temperature and surface roughness in grinding …
In this technology, a little quantity of 0°C water is carried by high pressure cryogenic air (-20°C) and reaches the grinding zone in the form of high speed mist jet to enhance heat transfer and ...
In this research, the cooling performance of nano-particle jet MQL was analyzed. Based on tests and experiments, the surface temperature was assayed from different methods, including flood lubricating oil, dry grinding, MQL grinding and nano-particle jet MQL grinding.
On the basis of research on the thermal effect in grinding contact zone during high efficiency grinding, an idea of enhancing heat transfer in contact zone using high pressure water jet impinging is advanced. Fundamental heat transfer experiments on enhancing heat transfer with high pressure water jet impinging were completed. The maximum speed of jet impinging reaches 110m/s. The experimental ...
FIS analysis of slotted and unslotted workpieces indicates a high material-removal rate is achieved with an unslotted workpiece and intermediate coolant flowrate of 3.1 l/m/mm. Plot of ratio of coolant flow vs. hp/unit width shows coolant flow is sufficient to quench grinding …
However, high-pressure coolant (HPC) jet effectively reduces cutting zone temperature entering into chip tool interface maintaining a good surface integrity. The present work investigates the role of high-pressure coolant jet on chip formation, grinding zone temperature and surface roughness in grinding …
One potential beneficiary of this coolant approach is the multitasking turning center. Most of these machines offer optional coolant supply at pressures between 70 to 100 bar. In fact, Coromant has developed high-pressure coolant accessories specifically for use with these machines at that amount of pressure.
The only useful measure to avoid this turbulence is a distinct increase of the coolant jet velocity by increasing the feeding pressure up to 15 – 20 bar (and often more). Thus the coolant jet velocity comes closer to the grinding wheel velocity, so lower whirling and better adhesive wetting of the work piece surface is obtained.
Effect of high pressure coolant jet on cutting temperature, tool wear and surface finish in turning hardened (HRC 48) steel, Journal of Mechanical Engineering, 2015
To study the effect of high-pressure lubricoolant supply on tool temperature, reference tests also carried out using conventional overflood cooling (CoC). The results suggest that the tool temperature can be significantly decreased compared to CoC by applying the high pressure lubricoolant supply and using specially designed jet guidance ...
When the pressure exceeds a certain critical value (4 bar), the pressure continues to increase, resulting the reduction of cooling effect, the rise of grinding temperature, and the increase of the tensile stress caused by the grinding thermal load, which leads to the reduction of the residual compressive stress on the surface of the workpiece.
This high energy input helps Journal of Mechanical Engineering, Vol. ME 45, No. 1, June 2015 Transaction of the Mechanical Engineering Division, The Institution of Engineers, Bangladesh Effect of high pressure coolant jet on cutting temperature, tool wear and surface finish in turning hardened steel 5 the cutting zone temperature to increase.
The present investigation is an attempt to study the effects of jet application parameters, i.e., coolant pressure, angle of impingement of the jet, spot distance and nozzle diameter on tool wear and chip morphology and to compare the effectiveness while turning Ti-6Al-4V bars under high pressure cooling with neat oil.
(Similar results were obtained in simulated grinding tests by Powell et. al., 1978) Similarly, the supply pressure to a fluid jet affects the removal of heat from the grinding zone. Powell's studies have established a relationship between critical heat flux and coolant pressure as …
According to Lee et al. (2002), who conducted experiments in groove grinding, the compressed air jet is a tool that can be used to reduce clogging because the air impacts the wheel surface and removes a large number of the impurities that adhere to it (see Fig. 2).Consequently, a decrease in the wheel wear rate and an improvement in form accuracy can be achieved by using a high pressure air jet.
The high-pressure coolant jet is projected from the nozzles to provide localized cooling of the insert at the point of contact. The wedge effect assists in breaking chips into small pieces for speedy evacuation from the cutting area. Many turning operations can benefit from the strategic use of high-pressure coolant.
Warkentin, A, , RJ, Hartlen, D. Comparison of conventional, coherent-jet and high-pressure coolant delivery systems for profile grinding. T Can Soc Mech Eng 2008; 32(1): 107 – 119. Google Scholar | Crossref
High-strength alloys have significant application values in aerospace industry due to their excellent mechanical properties. However, grinding of these alloys, which is generally used for precision machining, suffers from problems like high grinding temperature and poor surface quality. Having relatively lower grinding temperature and smaller grinding force, micro-grinding is a high-efficient ...
Dahlman P 2002 A comparison of temperature reduction in high-pressure jet-assisted turning using high pressure ... Machado A R and Wallbank J 1994 The effects of a high-pressure coolant jet on machining Proc. I. Mech. Eng ... R J and Warkentin A 2005 A review of cutting fluid application in the grinding process Int. J. Mach. Tool ...
The pressure, flow rate, temperature, and direction of the jet all influence the fluid's cooling ability. ... A dispersed jet pumps air and coolant into the grinding wheel, displacing some of the fluid with air. ... or 6 kW) on the plated wheel, and 40% (12 hp or 9 kW) on the vitrified wheel, for no change in the cycle parameters. No high ...
of the grinding wheel and the effect of air scrapers on the wheel boundary flow [13,14]. This work aims to contribute for the understanding of the interaction of the coolant jet of different nozzle types with the grinding wheel considering the airflow. As stated in [15] the Rouse shape nozzle is considered in
