Machining of Aluminum and Aluminum Alloys / 763
ASM Handbook, Volume 16: Machining Copyright © 1989 ASM International® ASM Handbook Committee, p 761-804 All rights reserved. DOI: 10.1361/asmhba0002184 www.asminternational.org MachJning of Aluminum and AlumJnum Alloys ALUMINUM ALLOYS can be ma- -r.. _ . lul Tools with small rake angles can normally chined rapidly and economically. Because be used with little danger of burring the part ," ,' ,,'7.,','_ ' , '~: £,~ " ~ ! f / "' " of their complex metallurgical structure, or of developing buildup on the cutting their machining characteristics are superior ,, A edges of tools. Alloys having silicon as the to those of pure aluminum. major alloying element require tools with The microconstituents present in alumi- larger rake angles, and they are more eco- num alloys have important effects on ma- nomically machined at lower speeds and chining characteristics. Nonabrasive con- feeds. stituents have a beneficial effect, and ,o IIR Wrought Alloys. Most wrought alumi- insoluble abrasive constituents exert a det- num alloys have excellent machining char- rimental effect on tool life and surface qual- acteristics; several are well suited to multi- ity. Constituents that are insoluble but soft B pie-operation machining. A thorough and nonabrasive are beneficial because they e,,{' , understanding of tool designs and machin- assist in chip breakage; such constituents s,~ ,.t ing practices is essential for full utilization are purposely added in formulating high- of the free-machining qualities of aluminum strength free-cutting alloys for processing in alloys. high-speed automatic bar and chucking ma- Strain-hardenable alloys (including chines. " ~ ~p /"~ commercially pure aluminum) contain no In general, the softer ailoys~and, to a alloying elements that would render them lesser extent, some of the harder al- c • o c hardenable by solution heat treatment and ,p loys--are likely to form a built-up edge on precipitation, but they can be strengthened the cutting lip of the tool.
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