PSI - Issue 2_B

Su Jie et al. / Procedia Structural Integrity 2 (2016) 2222–2229 Su Jie et al. / Structural Integrity Procedia 00 (2016) 000 – 000

2224

3

500

400

300

2024-T4 in-situ PRAMC

200

Nominal stress/MPa

100

0

0.00

0.02

0.04

0.06

0.08

0.10

Nominal strain

Fig. 1 Nominal stress-strain curves of in-situ TiB2/2024 PRAMC and 2024-T4 alloy

10 mm

3.5 mm

35 mm

Fig. 2 The geometry of the in situ tensile specimen

3. Observation of the fracture process

From the microscopic view of the observation surface (Fig. 3&4), the grain size of Al matrix is about 600  m × 100  m. Massive particles of very tiny sizes (tens to hundreds of nanometers) collected on grain boundaries to appear as the clusters of small particles (CSPs). Particles of such small sizes are scarcely distributed inside grains except for few of isolated large particles (LPs) up to dozens of microns.