PSI - Issue 2_A

Dariusz Boroński et al. / Procedia Structural Integrity 2 (2016) 3764 – 3771 Boro ń ski et al./ Structural Integrity Procedia 00 (2016) 000–000

3770

7

80

70

60

Al/Ti layered material AA2519 aluminum alloy Ti6Al4V titanium alloy

50

40

stress, MPa

30

20

10

0

0

0,5

1

1,5

2

2,5

3

COD, mm

Fig.9. Stress vs. COD curves for AA2519 aluminum alloy and Ti6Al4V titanium alloy for cryogenic conditions

For comparative purposes, the tests results were referred to the values of K Q determined for component materials. The Figure 9 shows tensile diagrams for CT specimens made of a titanium and aluminum alloy in cryogenic conditions. The values of K Q determined in the tests are presented in Table 3.

Table 3. Values of K Q determined for: Al/Ti explosive welded layered material, AA2519 aluminum alloy and Ti6Al4V titanium alloy Material Temperature K Q (mean value) AA2519 77 K 38.6 MPa·m 0.5 Ti6A14V 77 K 66.5 MPa·m 0.5 Al/Ti 77 K 41.8 MPa·m 0.5 Al/Ti 297 K 47.1 MPa·m 0.5

A comparison of tests results allowed to find out that crack resistance of a multi-layer material Al/Ti under cryogenic conditions does not differ significantly from the one determined for the ambient temperature. However, there are significant differences in crack resistance between component materials and Al/Ti composite particularly in reference to the titanium alloy. Crack resistance of titanium described by K Q parameter is almost twice higher than crack resistance of aluminum alloy and almost 60 % higher than crack resistance of Al/Ti composite. Thus, it can be said that application of titanium increased crack resistance of the aluminum alloy, however less than aluminum reduce crack resistance of the titanium.