Circular and square cups drawing and ironing of Ti alloy sheets by incremental press forming method

The low ductility of Ti–6Al–4V alloy at forming temperatures below 780°C is still a problem. Ti–6Al–IV alloy is usually hot press formed at 780 to 900°C. Hence, it is necessary to develop a new press forming for Ti–6Al–4V alloy sheets at forming temperatures below 780 °C to improve productivity. A new method to achieve of warm and cold press forming of Ti–6Al–IV alloy sheets by combining press motion control and clearance between a die and a blank was developed. In this study, the various forming conditions for developed press forming method were confirmed. In this method, the following two processes were separated: punch motion process without Blank Holding Force(BHF) and BHF motion process without punch motion. These two processes were carried out alternately during deep drawing or drawing and ironing. Three forming parameters, namely, the punch speed Spi, punch stroke Psi, and blank holding force BHFi, were controlled separately and the effect of forming conditions on deformation behavior was investigated by using experiment and finite element analysis(FEA). As a result, the circular and square cups drawing and ironing of Ti alloy sheets were achieved by applying developed method.