Improvement of the Erichsen Values of Titanium Sheets Using Various Cereal Flour Lubricants

The lubrication by various cereal flours, such as wheat flour, rice flour, and so on, was studied to develop a nonpolluting lubricant for sheet metal forming. The lubricants were prepared in the following way. (1) Each cereal flour was dissolved in water at several concentrations. (2) Each suspension was coated on a titanium sheet. (3) The specimens were dried and cereal particles, thus, remained on the both surfaces of a specimen. The performance of these lubricants were evaluated by the Erichsen cupping test. Most of the flours show higher Erichsen values than grease. Furthermore, the cereal particles on the deformed specimens were observed by scanning electron microscopy, and analyzed by electron probe microanalyzer. The observations suggest that the starch particles covered with protein and lipid can reduce the friction between dies and a specimen.