Titanium alloys are divided into three types according to the structure in the annealed state: α type, β type and α+β type. The brand name is "T" followed by A, B, C and sequential numbers, such as TA4~TA8 indicating α type; TB1~TB2 indicating β type; and TC1~TCl0 indicating α+β type.
α-type titanium alloy has low room temperature strength (σb is about 850 MPa), but its high-temperature (500~600℃) strength (σb=400 MPa at 500℃) and creep strength rank first among titanium alloys; and the structure of this type of alloy It is stable, has excellent corrosion resistance, good plasticity and processability, and also has excellent welding performance and low temperature performance; β-type titanium alloy has good plasticity and toughness in the quenched state and good cold formability; however, the alloy has high density and the structure is not stable enough , has poor heat resistance and is not widely used; α+β titanium alloy has the characteristics of α and β titanium alloys, has very good comprehensive properties, and is the most widely used.
The composition of TC4 titanium alloy is Ti-6Al-4V, which is an (α+β) type titanium alloy. It has good comprehensive mechanical and mechanical properties, high specific strength, excellent corrosion resistance, good biocompatibility, etc. and is widely used. Aerospace, petrochemical, biomedicine and other fields. This article compares several main preparation methods for 3D printing titanium alloy powder, chooses the plasma rotating electrode method to prepare titanium alloy powder, discusses the balling mechanism of titanium alloy powder, conducts exploratory research on the evolution of its microstructure, and discusses The main heat treatment methods are identified to provide the necessary theoretical basis for the application of 3D printing technology TC4 titanium alloy.
(1) TC4 titanium alloy powder prepared by the plasma rotating electrode method has a powder particle shape that is very close to spherical, with a smooth surface, good fluidity, and good powder characteristics, which meets the requirements of 3D printing.
(2) The microstructure of the cross-section of TC4 titanium alloy is columnar crystals that radiate from the temperature center to the edge. The microstructure of the longitudinal section is columnar crystals that grow along the direction of the stacking layer. The control of the heat source energy can effectively control the temperature of TC4 titanium. The microstructure of the alloy.
(3) The heat treatment is solid solution + aging, and the air cooling method effectively improves the strength and plasticity of the deposited TC4 titanium alloy, making its performance meet the requirements of TC4 titanium alloy 3D printing.
