Shaanxi Yunzhong Industry Development Co.,Ltd
Address: NO.128 Gaoxin Road, Baoji City, Shaanxi Province of China
The performance of titanium alloy has low density, high specific strength, good corrosion resistance, no magnetism is excellent, in aerospace, chemical, automobile, ships, weapons, sports, medical and other fields is an important structural material. However, the high cost limits its scope of application. Therefore, the research and development of low cost titanium alloys and the low cost preparation technology of titanium alloys are still the most important research topics. Reducing the cost of raw materials and shortening the processing flow are the effective ways to reduce the cost of titanium alloy......
The effects of electron beam cold hearth melting (EBCHM) and properties of TC4 titanium alloy ingot in direct rolling deformation and annealing process of the organization, reveals the evolution of microstructure and mechanical properties of the sheet, the best matching and annealing system of plastic material strength, the alloy sheet provide the basis for industrialized batch production.
1 test materials and methods
The use of titanium sponge and titanium alloy return material and other raw materials in the electron beam cold hearth melting on a 270 x 1085 x 5000 mmTC4 titanium alloy ingot, its chemical composition meets the requirement of GB/T 3620.1-2007 standard, metallography measuring the beta transition temperature of 974 DEG C. After the treatment, the ingot is used on the 1200 mm four roller reversible hot rolling mill, which is below the transformation point from 20 to 50 DEG c......
2 test results and discussion
2.1 the microstructure and properties of sheet during deformation
Figure 1 is the microstructure of TC4 titanium alloy plate after different deformation. From Figure 1 (a) of TC4 titanium alloy electron beam cold hearth melting visible flat ingot coarse grain, grain for dendritic structure. After the deformation of a fire, the cast dendritic structure was broken into a columnar structure, as shown in Figure 1 (B). After two fire, the coarse grain is broken into fine grain......
Microstructure and properties of 2.2 annealed sheet
Figure 2 is the microstructure of the plate after annealing at to 950 DEG C for /1h and AC. It can be seen from the figure, when the annealing temperature is low (720 ~ 820) C, while the microstructure of some changes, but still with a rod or equiaxed alpha + beta microstructure, grain size and shape are very similar (see 2A ~ d). With the increasing of annealing temperature from 820 DEG C, the microstructure of the plate changed obviously at low temperature......
1) with the increase of rolling deforming time, casting grain of TC4 titanium alloy electron beam cold hearth melting ingot coarse broken dendrite into * * organization, significantly improve the mechanical property of the sheet at room temperature;
2) TC4 titanium alloy sheets after annealing, the organization is more uniform equiaxed, as the temperature increases, the secondary precipitation of lamellar alpha phase, the primary content of the tensile strength of * *; * * * * after the first trend, yield strength and contraction rate showed an overall trend but the elongation is * *, little change;
3) the best match of strength and plasticity can be obtained after annealing treatment.