Abstract
The turning tests were made on three sorts of wrought aluminium, that is, 11S which is well known as most machinable one, 17S which is looked upon typical high tension aluminium and 56S which is used as anti-corrosive alloy, and their machinability were examined. It seems that the machinability must be discussed upon several factors, for example, the cutting resistance, the roughness of turning surface, the tool life, the chip formation, the chip disposal and others. In this paper, the cutting force and the chip disposal are mainly studied and in the following report, the roughness of turning surface and the built-up edge will be discussed. The results are summarized as follows:
1) The larger the rake angle of tool, the smaller the cutting resistance, and in the case of 17S and 56S, especially, the cutting resistance increases radically when the rake angle gets less than 10°. The cutting resistance is not affected by the cutting speed (in this experimental case, 37-183m/min), and the resistance increases in proportion to the increasing in the feed in constant rake angle.
2) The cutting resistance increases in order of 11S, 56S and 17S, and it seems that there is no connection between the resistance and the tensile strength or the hardness.
3) The trouble seems to increase in the chip desposal in order of 11S, 56S and 17S. In the case of 17S, especially, a continued straight flow type chip is apt to grow, for which a chip breaker is necessary.
