Comparative Studying Of TC4 Titanium Alloy Prepared By 3D Printing,Traditional Casting And Forging

TC4 titanium alloys are fabricated by laser rapid prototyping(3D printing),forging and casting.Microstructure and phase composition are analyzed by optical microscope,scanning electron microscope and X-ray diffractometer.The tensile properties are also studied by mechanical performance testing equipment.The results show that the microstructure and properties of the 3D printing titanium alloy have obvious orientation.The strength and elongation of the transverse direction of the sample are 1007 MPa and 9.30%respectively,while those of longitudinal direction are 950 MPa and 15.28%respectively.The strength and elongation of the forging TC4 alloy are 877 MPa and 18.00%respectively.The strength and elongation of casting TC4 are 836 MPa and 3.92%respectively.The difference in mechanical properties of samples by different forming methods comes from the different microstructures and grain sizes that they form.3D printing TC4 titanium alloy samples form a basket structure during the rapid cooling process.And the grain is very small,about 2-3?m.The forging sample is formed into an equiaxed structure with a grain size of about 10 ?m.And the microstructure is more uniform than 3D printing and casting alloys,thus having a higher elongation.The Widmanstatten structure is formed in the casting sample,the grain size reaches 20?25 ?m,and the tissue distribution is also uneven.Therefore,it has lower mechanical properties.ABAQUS software is used to simulate the mechanical response of parts prepared by the above three different processes under shock conditions(free fall and contact the ground).The research shows that the forging sample has the largest maximum strain,followed by the 3D printing longitudinal sample,3D printing transverse sample,and the casting sample has the minimal maximum strain.This is consistent with the plasticity results obtained from the previous tensile test.And it proves that 3D printing TC4 titanium alloy has good impact deformation resistance.