Minimal lubrication machining of aluminium alloys
Section snippets
Machining of aluminium alloys
Aluminium alloys are amongst the most machinable of the common metals [2]. Cutting forces are generally low and because aluminium is a good conductor of heat and since most aluminium alloys melt at temperatures between 500 and 600 °C, cutting temperatures and tool wear rates are also low. When cut under proper conditions with sharp tools, aluminium alloys acquire fine finishes through turning, drilling and milling, minimising the necessity for grinding and polishing operations. Aluminium is
Selection of a cutting fluid
The proper selection of a cutting fluid is a factor that is sometimes unfortunately neglected in machining practice. Considerable effort is usually put when choosing the correct tooling, workpiece stock and machining parameters, yet too often, only a cursory review of existing cutting fluid technology is completed in selecting an appropriate cutting fluid. Some of the factors considered have nothing to do with the particular metal cutting operation, but rather concern the ease of cleaning the
Experimental appraisal of the drilling process
A set of experiments was performed to investigate the role of different coolant application methods in the drilling of a 30 mm aluminium alloy ACP 5080 plate with a Brinell hardness of 85. Drilling was carried out on a Hurco BMC-20 three-axis computerised numerical control (CNC) machining centre using a 10 mm high speed steel twist drills. To ensure uniformity of chemical composition, microstructure and other properties, a group of drills from the same batch were purchased and used throughout the
Drill wear and feed force variations
With respect to the measurement of drill wear, it was frequently observed that this measurement was obscured by the high tendency of aluminium material to adhere to the portion of interest at the drill point, and thus in many cases the attempts at measurement were abandoned. From Fig. 4, it can be observed that a reduction in feed force is obtained in general for all methods of coolant application with an increase in cutting speed and feed rate. However, the reduction in feed force observed
Conclusion
The promising results obtained during the course of this research suggest that the future of drilling lubrication lies in minimum quantity lubrication. The amount of lubricant used in mist lubrication is minuscule compared to that used in traditional flood lubrication. From research, it is believed that the alignment of the feed nozzle in relation to the tool, the volume flow of the cutting fluid and the pressure of the cutting fluid may be optimised to maximise tool life for both flood and
Acknowledgements
The authors gratefully acknowledge the financial assistance provided by Enterprise Ireland under the Applied Research Programme.
References (6)
- B. Chamberlain, Machinability of Aluminium Alloys, Metals Handbook, Vol. 2—Properties and Selection: Nonferrous Alloys...
- E.M. Trent, Metal Cutting, Butterworths, London, 1977, pp....
Trans. Am. Soc. Mech. Eng.
(1955)