TY - GEN
T1 - Damage accumulation profile and fraetnre event sequence of particulate metal matrix composite monitored by acoustic emission
AU - Bussiba Dr, A.
AU - Carmi, R.
AU - Haroush, S.
AU - Alon, I.
AU - SHNECKProfessor, R.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Particulate reinforced metal matrix composite A1-A356/SiC with volume fraction of 50% has been characterized mechanically and simultaneously by acoustic emission (AE) method. The composite consists of trimodal particle reinforcement distribution of 35pm, 15pm and 8pm sizes. High precision extensometer and LVDT were used in order to determine the modulus, yield stress and fracture strain. Common and advanced AE data analysis were used in order to point out on the damage accumulation profile, sequence events during the fracture process and the microfailure mechanisms and their dominance in the different stages of the mechanical behavior. SEM and metallographies studies were applied to get a comprehensive picture of the fracture mechanisms. Under uniaxial tensile stress, the material behaves in a quasi-brittle manner with high modulus (185 GPa) and low fracture strain (0.25%). The AE cumulative profile shows three stages of damage: parabolic, linear and exponential, each represents a different dominant fracture mechanism; particle cracking, de-cohesion and void coalescence respectively. This has been verified by weighted peak frequency displays combined with partial loading and tracking on the deformed polished specimen. In bending mode, similar mechanical and acoustic behaviors were observed with the same three stages of damage. However, where anisotropic condition was examined completely different AE cumulative profile was detected in which mainly damage with exponential behavior was occurring. In fracture toughness tests, it was observed that as the notch radius decreases the toughness decreases and the valid value was estimated using a modified fracture model. AE response exhibited only the linear and the exponential stages which has been correlated to the sampled volume near the vicinity of the notch tip. FFT and STFFT analysis indicated low characteristic frequency for the void coalescence mechanism and the higher one for the particle cracking. As well, on the time domain display the particle cracking initiated first, followed by de-cohesion particle/matrix and ended by void coalescence of the matrix.
AB - Particulate reinforced metal matrix composite A1-A356/SiC with volume fraction of 50% has been characterized mechanically and simultaneously by acoustic emission (AE) method. The composite consists of trimodal particle reinforcement distribution of 35pm, 15pm and 8pm sizes. High precision extensometer and LVDT were used in order to determine the modulus, yield stress and fracture strain. Common and advanced AE data analysis were used in order to point out on the damage accumulation profile, sequence events during the fracture process and the microfailure mechanisms and their dominance in the different stages of the mechanical behavior. SEM and metallographies studies were applied to get a comprehensive picture of the fracture mechanisms. Under uniaxial tensile stress, the material behaves in a quasi-brittle manner with high modulus (185 GPa) and low fracture strain (0.25%). The AE cumulative profile shows three stages of damage: parabolic, linear and exponential, each represents a different dominant fracture mechanism; particle cracking, de-cohesion and void coalescence respectively. This has been verified by weighted peak frequency displays combined with partial loading and tracking on the deformed polished specimen. In bending mode, similar mechanical and acoustic behaviors were observed with the same three stages of damage. However, where anisotropic condition was examined completely different AE cumulative profile was detected in which mainly damage with exponential behavior was occurring. In fracture toughness tests, it was observed that as the notch radius decreases the toughness decreases and the valid value was estimated using a modified fracture model. AE response exhibited only the linear and the exponential stages which has been correlated to the sampled volume near the vicinity of the notch tip. FFT and STFFT analysis indicated low characteristic frequency for the void coalescence mechanism and the higher one for the particle cracking. As well, on the time domain display the particle cracking initiated first, followed by de-cohesion particle/matrix and ended by void coalescence of the matrix.
UR - http://www.scopus.com/inward/record.url?scp=84961354481&partnerID=8YFLogxK
M3 - Conference contribution
T3 - Proceedings of the American Society for Composites - 29th Technical Conference, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting
BT - Proceedings of the American Society for Composites - 29th Technical Conference, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting
PB - DEStech Publications
T2 - 29th Annual Technical Conference of the American Society for Composites, ASC 2014; 16th US-Japan Conference on Composite Materials; ASTM-D30 Meeting
Y2 - 8 September 2014 through 10 September 2014
ER -