TY - JOUR
T1 - Effects of thermal residual stresses and thermal-induced geometrically necessary dislocations on size-dependent strengthening of particle-reinforced MMCs
AU - Cao, Dongfeng
AU - Duan, Qingfeng
AU - Li, Shuxin
AU - Zhong, Yucheng
AU - Hu, Haixiao
PY - 2018/9/15
Y1 - 2018/9/15
N2 - The thermal residual stresses (TRSes) can noticeably increase the yield strength and flow stresses of particle-reinforced metal-matrix composites (PR-MMCs) and show size-dependence due to thermal geometrically necessary dislocations (GNDs) when the size of particles is on the order of micron. This TRSes strengthening is attributed to the conventional thermal-elasto-plastic constituent mismatch (regardless of particles’ size) and the presence of GNDs (size-dependent). A modified Taylor-based nonlocal theory (TNT) of plasticity is proposed to quantify the individual contributions of size-dependent GND strengthening. An axisymmetric unit-cell model of uniform and aligned particle distribution with various particle sizes is built to study thermal-induced non-uniformly distributed GNDs, their evolution and contributions to the stress strengthening under combined thermal and mechanical loading. The results show that the proposed methodology can effectively capture the size dependence of thermal-induced GNDs which keeps a sharp gradient variation in the zone near the matrix-inclusion interface and gradually flattens out in the zone far away from the interface. It is demonstrated that TRSes significantly improve the yield strength and flow stresses. It also revealed that the contribution of thermal-induced GNDs increased as the particle size in the PR-MMCs decreased. The simulation results were validated by experimental results reported in the literature.
AB - The thermal residual stresses (TRSes) can noticeably increase the yield strength and flow stresses of particle-reinforced metal-matrix composites (PR-MMCs) and show size-dependence due to thermal geometrically necessary dislocations (GNDs) when the size of particles is on the order of micron. This TRSes strengthening is attributed to the conventional thermal-elasto-plastic constituent mismatch (regardless of particles’ size) and the presence of GNDs (size-dependent). A modified Taylor-based nonlocal theory (TNT) of plasticity is proposed to quantify the individual contributions of size-dependent GND strengthening. An axisymmetric unit-cell model of uniform and aligned particle distribution with various particle sizes is built to study thermal-induced non-uniformly distributed GNDs, their evolution and contributions to the stress strengthening under combined thermal and mechanical loading. The results show that the proposed methodology can effectively capture the size dependence of thermal-induced GNDs which keeps a sharp gradient variation in the zone near the matrix-inclusion interface and gradually flattens out in the zone far away from the interface. It is demonstrated that TRSes significantly improve the yield strength and flow stresses. It also revealed that the contribution of thermal-induced GNDs increased as the particle size in the PR-MMCs decreased. The simulation results were validated by experimental results reported in the literature.
KW - Geometrically necessary dislocation (GND)
KW - Metal matrix composites (MMCs)
KW - Strain gradient theory
KW - Thermal residual stresses
UR - http://www.scopus.com/inward/record.url?scp=85047835364&partnerID=8YFLogxK
U2 - 10.1016/j.compstruct.2018.05.129
DO - 10.1016/j.compstruct.2018.05.129
M3 - Article (Academic Journal)
AN - SCOPUS:85047835364
VL - 200
SP - 290
EP - 297
JO - Composite Structures
JF - Composite Structures
SN - 0263-8223
ER -