Yuzo Takatsuji

Effect of Fe, Si content on the machinability of 5056 alloy.

Dry cutting tests of 5056 alloys which were added Fe (0.014-0.19wt%) and Si (0.006-0.07wt%) were made using high speed steel (SKH4) and sintered carbide tool (K10). Effect of these elements on the machinability was studied from the viewpoints of cutting resistance, built up edge, cut surface roughness, tool wear and chip disposal.(1) Under a low cutting speed, machined surface of all specimens were rough and scaly for forming of built up edge. However, under a high cutting speed, feed marks on machined surface appeared clearly and its roughness value was low. Especially the finished surface of alloy which contains less Fe and Si approximated to the theoretical value.(2) Following the increase of Si content which formed metallic compound Mg2Si in this alloy, the tool wear rates on flank and rake face were rapid. In increasing Fe content which formed metallic compound Al-Fe, the rake face wear progressed rapidly. But, it was less affected with the flank wear rates.