10 A Novel High-Efficiency Keyhole Tungsten Inert Gas …
361
Fig. 10.46 Tensile property
of the BM and WM
Table. 10.12 AE of the BM
and WM [45]
Welding current (A)
Absorbed energy, Akv (J)
510
20.4
530
32.1
550
33.6
BM
24.3
10.5.2.2 Impact Property
In this section, the notch samples are mainly made at the BM and WM, and the
Charpy impact tests are used to examined the AE of the BM and WM. The AE of the
BM and the WM obtained under different welding currents is shown in Table 10.12.
When the welding current are 510 A, 530 A and 550 A, the mean value of the AE of
the WM are 20.4 J, 32.1 J and 33.6 J, respectively. The impact test results show that
when the welding current is 510–550 A, with the increase of the welding current,
the AE of the WM is gradually increased. When the welding current is 530 A or
550 A, the mean value of the AE of the WM is higher than that of the BM. When
the welding current is 510 A, the mean value of the AE of the WM is slightly lower
than the BM, but reached 84% of the BM.
10.5.3 Microstructural Characterization
The microstructure of TC4 titanium alloy can directly affect the tensile and impact
properties of the material. During the welding process, affected by the temperature,
the structure of the HAZ and the WM will change significantly. The HAZ and the WM
are the main areas that affect the performance of the welded joint. In this section, we
take a K-TIG welded joint with a welding current of 550 A as an example to introduce
the evolution characteristics of the microstructure of each area of the TC4 titanium
361
Fig. 10.46 Tensile property
of the BM and WM
Table. 10.12 AE of the BM
and WM [45]
Welding current (A)
Absorbed energy, Akv (J)
510
20.4
530
32.1
550
33.6
BM
24.3
10.5.2.2 Impact Property
In this section, the notch samples are mainly made at the BM and WM, and the
Charpy impact tests are used to examined the AE of the BM and WM. The AE of the
BM and the WM obtained under different welding currents is shown in Table 10.12.
When the welding current are 510 A, 530 A and 550 A, the mean value of the AE of
the WM are 20.4 J, 32.1 J and 33.6 J, respectively. The impact test results show that
when the welding current is 510–550 A, with the increase of the welding current,
the AE of the WM is gradually increased. When the welding current is 530 A or
550 A, the mean value of the AE of the WM is higher than that of the BM. When
the welding current is 510 A, the mean value of the AE of the WM is slightly lower
than the BM, but reached 84% of the BM.
10.5.3 Microstructural Characterization
The microstructure of TC4 titanium alloy can directly affect the tensile and impact
properties of the material. During the welding process, affected by the temperature,
the structure of the HAZ and the WM will change significantly. The HAZ and the WM
are the main areas that affect the performance of the welded joint. In this section, we
take a K-TIG welded joint with a welding current of 550 A as an example to introduce
the evolution characteristics of the microstructure of each area of the TC4 titanium