Deposited copper as lubrication when drawing of titanium wire; a study of method.
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
This work performed at Sandvik Materials Technology has studied the possibility of using copper as lubrication during Ti-wire drawing. A PVD-method was used to deposit Cu on Ti-wires. The PVD coated copper samples were compared to a reference material of solid Cu which first had to be recrystallized. Different reduction combinations were investigated in the wire drawing and the Cu-coated wires were drawn both without and with MoS2 lubrication. Values, including drawing forces, HV and tensile testing, from already drawn Ti-wires without Cu were included in the matrix and the drawing forces were then compared. Significant contributions of friction were present in the first draw of all unlubricated Cu-coated Ti-wires. The forces decreased considerably after the first draw. After four drawings, done on one of these wires, the forces then were in the same region as the lubricated wires at the same reductions. No clear tendencies of uneven hardening were observed regardless of friction or used reduction. Tensile testing after wire drawing could not be performed as the wires broke at the wrong places. Measurements of residual stress on worked and unworked Cu-layers showed no residual stress, surprisingly. This study shows that Cu can be used as lubrication if the process is optimized with respect to Cu layer thickness, drawing tool-angles and reduced tungsten carbide grain size in drawing tools. A smoothening draw is needed before reduction of the Ti-wire to help lower the friction.
Place, publisher, year, edition, pages
Sandvik, copper layer, friction, pulling forces, wire drawing, drawing tool angle.
Other Materials Engineering
IdentifiersURN: urn:nbn:se:du-21308OAI: oai:DiVA.org:du-21308DiVA: diva2:916190