Effect of Si content on machinability of Al-Si alloys

Abstract

This study investigates the effect of the change in the amount of Si found in Al-Si alloys on mechanical properties and machinability properties of the alloy. The way the microstructure and the mechanical properties change depending on the increase in the %Si amount in the alloy and the effects of such changes on Flank Build-up (FBU), wear in the cutting edge, surface roughness, and machinability were analysed. To this end, alloys with varying amounts of silicon (i.e., 2 to 12 wt.% Si) were used in the study. Experimental samples were obtained by casting in sand moulds. It was observed in the study that, in Al-Si alloys, the mechanical properties and machinability of alloys increased depending on the rise in %Si in the alloy, that cutting forces decreased, and accordingly, machinability increased. It was also observed in the study that the increase in the %Si amount raised the surface quality (decrease in surface roughness).K e y w o r d s : machining, cutting force, mechanical properties, Al-Si alloys

Fabrication of Zinc Oxide Resistive Random-Access Memory on a Flexible Polyimide Substrate with Different Thicknesses

“…5b), where the signal peaks of ZnO (002) and Al can be observed, indicates that the prepared ZnO film has a single-crystal structure. 16,17 The devices were fabricated with different PI film thicknesses, and their electrical properties were measured in flat and curved states. Figure 6a shows a photograph of the device in the flat state.…”

Correlation between the microstructure and machinability in machining Al–(5–25) wt% Si alloys

“…The axial component of cutting force became significantly higher when turning hypoeutectic Al−Si alloys with higher Si content, while the tangential component of cutting force was hardly affected by the Si content. 26 Akyüz 27 also reported that the decreased cutting forces with the increase in Si content lead to an improvement of machinability in machining hypoeutectic Al−Si alloys. In fact, transformation of coarse silicon particles to fine fibrous structure enhances the machinability of hypoeutectic Al−Si alloys by exhibiting the lowest BUE.…”

“…The reason can be attributed to the reduction of BUE at high cutting speeds. 27 Farid et al 29 indicated that the uncontrollable thrust force should be addressed to have full benefits of high-speed drilling of Al−Si alloys. The results indicated that cutting speed had the highest contribution to thrust force.…”

“…The chip manifests more brittle or fragile behaviors as the rising of hardness with increasing Si content, as well as the rising of cutting speed. 27 Farid et al 32 indicated that higher cutting speeds led to the formation of fan-shaped chips rather than conical chips in drilling Al−11.5Si alloy because of the reduction of BUE. The formation of fan-shaped chips promoted the reduction in surface roughness of the hole.…”

Effects of Trace Elements on the Microstructural and Machinability Characteristics of Al–Si–Cu–Mg Castings

“…Akyüz [ 16 ] reported that cutting efficiency was improved in Al-13%Si alloys containing 0.2~0.4%Sn; thus, the cutting resistance was decreased, the cutting temperature was lowered, and the progress of tool wear was retarded. The improvement in machined surfaces was not clearly defined, although the treatment of chips became easier because their shape had changed to a sheared form.…”