THE IMPACT OF CIRCULAR DIE PROFILES ON PARAMETERS OF LABORATORY EXTRUSION
In order to improve the hardness property and quality of extrudates products under metal flow conditions, and investigate into extrusion pressures and defects (piping and deflection). The study aimed to investigate the impacts of die profiles and land, die shape, inner extrusion pressure ratio and ram pressure on die reduction in area using experimental means. An experimental test was conducted using designed, modified and constructed laboratory extrusion rig and scrap lead metal from automobile batteries. The scrap had a lead metal yield strength of 17 Mpa and was cast and machined to billets diameter of 24.5 mm by 24 mm lengths. The die diameters used to extrude the billet were 11 mm, 15 mm, 16 mm, 20 mm, and 22 mm. The impacts of inner extrusion pressure ratio, ?P_i??f?_ on die reduction in area R*=1/(1-r) was observed. It showed that the inner extrusion pressure ratio increased from 0.85 to 2.68 for die reduction in area of (1.23 to 2.68). Hence the results for inner extrusion pressure ratio on die reduction in area increases significantly with increase in die profiles as well as die shape. The die land influences increase in inner extrusion pressure. The correlation coefficients of ?P_i??f?_ along its regression line was calculated and the plane-strain equation was used to evaluate the reliability of the results which showed a^' = 0.56 and b^'=1.36 for inner extrusion pressure which are satisfactory. The study also examined the impact of ram pressure on die reduction in area for piping, radius of curvature, and hardness properties of extrudates. The results finding indicated that, an increase in ram pressure led to an increase in both piping and radius of curvature, and the hardness of the extrudates improved, with average hardness values of 66.8R_C for R* = 0.21 compared to 52.2R_C for R* = 1.56. Additionally, average hardness values for R* = 0.84 and R* = 0.40 were shown at 36.5R_C and 32R_C respectively. It was discovered that the extruded products increased along their circumferential solid positions with a rise in die reduction in area and increased with an increase in ram pressure.
Authors : Shettima, I.I., Hammajam, A.A., Onuh, S.O. and Kolo, L.A.M.
Category : Open Access Volume (Issue) : 10(2) Date Uploaded : 16th January 2025