Evaluation of 3D printing for dies in low volume forging of 7075 aluminum helicopter parts

Abstract

PurposeTo investigate the ProMetal 3D printing technique for its application to dies, for low volume hot forging of 7075 aluminum helicopter parts.Design/methodology/approachThermo‐mechanical and tribological behavior of the ProMetal 3D printed tools were characterized by hot upset and ring tests. Finite element simulations of the test application were conducted using special purpose metal forming simulation software FORGE3. Results obtained from the tests along with finite element analysis were used to validate behavior of the printed dies during forging trials.FindingsProMetal‐printed materials exhibited relatively low thermal conductivity and high friction. Cavities were printed, machined and evaluated in hot forging trials. Dies exhibited substantial settling during the manufacturing (3D printing) process. Some collapse of dies was also observed at locations where forging pressures were high.Practical implicationsAfter initial plastic settling, the printed dies provide satisfactory part tolerance for die temperatures and pressures up to 338°C and 689 MPa, respectively. Low thermal conductivity observed indicate a potential to forge aluminum with cooler dies. Coating or secondary polishing is necessary to achieve acceptable surface finish for forging of aluminum.Originality/valueThis paper demonstrates a need in RP industry to methodically match capabilities of the rapid prototyping process to the needs of the intended application through the use of finite element method and some fundamental characterization.