MICRO FORMING OF TITANIUM

Titanium is a popular material for medico components, primarily due to its excellent properties as regards strength, resistance to corrosion and biocompatibility. The disadvantages are mainly the low formability at room temperature and the material cost. As an alternative to conventional machining, the component can be plastically formed by a number of warm forming operations. Commercial pure titanium, grade 1, 2 and 4, is tested in 4 dimensions to investigate the size effect as function of temperature and strain rate. From these tests, a heat treatment procedure is derived and reliable data for a numerical model is acquired. The concept is validated by forming a dental implant. Due to the high aspect ratio of the tool inserts, a segmented die design is proposed. A two-step process design with pre-stressed die inserts is realized; following from the high yield strength of the titanium material that causes internal pressures above 2500 MPa under forging. The design phase is supported by numerical modeling.