Machining of LM13 and LM28 cast aluminium alloys: Part I

In present paper, the influence of melt treatment (grain refinement and modification) and heat treatment (T6) of cast LM13 and LM28 aluminium alloys on machining behaviour has been reported. Alloys under investigation were prepared by controlled melting and casting followed by heat treatment (T6). As-cast, melt-treated and heat-treated alloys were investigated for machining characteristic at different cutting speeds. Melt treatment of both the alloys (LM13 and LM28) reduced the cutting force and cutting temperature whereas heat treatment increased both cutting force and cutting temperature. Cutting temperature was found higher in machining of LM28 alloy than the LM13 alloy. Maximum cutting temperature was found for both the alloys in heat-treated conditions. Heat treatment of LM28 alloy reduced the surface roughness whereas heat treatment of LM13 alloy increased it. Melt treatment and heat treatment of LM13 alloy increased the average number of chips per gm. LM28 alloy produced higher number of chips per gm than the LM13 alloy.