CHARACTERIZATION OF SHEET METAL FORMABILITY OF BRASS CuZn30, GALVANIZED STEEL AND 1060 ALUMINUM ALLOY

In this work, the effect of annealing temperature on the formability of three different alloys (Brass CuZn30, Galvanized steel and 1060 Aluminum alloy) sheets was investigated both theoretically and experimentally. A range of annealing temperature, strain rate, and different lubrication conditions to determine best parameters for satisfactory metal forming.
Formability was tested by utilizing a special die and punch used in a prenow research. The annealed and as received sheets of the all three metals were tested using tensile test.For Brass (CuZn30) sheet, it was noticed that the best heat treatment which gives the largest dome height found when heated the sheet to 650 °C and then cooled it in iced water. This heat treatment improves the formability of brass sheet by 20.68%. For Galvanized steel sheet, it was noticed that the best heat treatment which gives the largest dome height found when heated the sheet to 550 °C and then cool it in air. This heat treatment improves the formability of Galvanized steel sheet by 28.8%. For 1060 aluminum alloy sheet , it was noticed that the best heat treatment which gives the highest dome height found when heated the aluminum sheet to 530 C° for 1hr, cooled it in iced water then put it in furnace with 150 °C for 2hr and left to cool on the furnace. This heat treatment improves the formability of aluminum sheet by 54%. Then for all this treated sheet was stretched by using different punch speeds to show which speed give us best formability it is found that 250 mm/min is the best punch speed. By using the best condition for annealing process and punch speed with different lubrication condition the results show that there is no tangible effect on the formability of metal, which is fulfill the purpose of this investigation to determine optimum annealing condition and optimum punch's speed and lubrication condition.One of the reliable method to represent materials formability is Forming Limit Diagram (FLD). Minor and Major strains of the FLD are found by printing a grid pattern of known diameters of circles on the surface of the specimens and then carrying out the test. After the test, these printed circles (1.7mm in diameter) are deformed and their axes measured by image processing method. Special software is programed for the purpose of minor and major strain measurements. Strain distributions along the stamped specimens are investigate and Force-Displacement curves are recorded for the specimens. Points from safe regions and unsafe regions are collected. Theoretical study was carried out to compare the results with the experimental results, good agreement has been shown according to the failure (fracture) position in each type of specimens.