Influence of Solidification Parameters and Solute Content on the Machinability of Two Lead-Free Babbit Metals

Abstract

Studies suggest that white metal Sn-Sb alloys are the most commonly type of babbit metal used in industry. However, it is necessary to evaluate manufacturing characteristics and solute contents that leads the best machining conditions. This work presents a correlation between solidification parameters and machinability of Sn-2.0wt%Sb and Sn-5.5wt%Sb alloys, solidified in a horizontal directional device, evaluating the influence of solute content on these results. Cutting temperatures were measured in dry necking processes along the length of the ingot. It was observed that the reverse cellular-dendritic transition influenced the cutting temperature results. The range of cell and dendrite spacings varies approximately from 40 to 330 μm on the Sn-2.0wt%Sb alloy and from 15 to 240 μm on the Sn-5,5wt%Sb alloy. In the cellular region, higher values are found for the Sn-5.5wt%Sb alloy, but in the dendritic region, these values were higher for the Sn-2.0wt%Sb alloy.