Influence of heat treatment and particle shape on mechanical properties of infiltrated Al₂O₃particle reinforced Al–2 wt-% Cu

Abstract

We regret that an error during revision and imposition resulted in an unacceptable quality of reproduction for Figs. 7 and 8 of the above paper. Improved versions of these gures appear below. a b c d a P15 composite, crack propagates by ductile voiding in matrix; b P25 composite, similar mechanism as for P15, but broken particles (indicated by arrows) are found; c A30, micrograph taken ahead of the main crack, in process zone: dominant fracture micromechanism is particle cracking (voids are arti®cially enhanced for clarity); d A5, particle cracking and matrix voiding (some broken particles are indicated by arrows) 7 Optical micrographs of crack path of arrested chevron-notch test showing dominant fracture micromechanisms

Fracture of aluminium reinforced with densely packed ceramic particles: influence of matrix hardening

“…Data gathered analogously from a preliminary study [34] are also reproduced hereafter to complete the present data. A minimum of two tests was performed for each material and heat-treatment condition, exception made for a few composites of low mechanical performance.…”

“…In a preliminary study of the influence of heat treatment on the mechanical response of Al-2wt%Cu matrix composites [34], it was found that coarse intermetallics formed at the matrix/reinforcement interface during solidification are responsible for a strong toughness degradation. The composites are therefore studied here in three conditions:…”

Investigation of crack-tip plasticity in high volume fraction particulate metal matrix composites

“…We present here results from a direct examination of crack-tip plastic zones in higher fraction ceramic composites, for which V f is comprised between 45% and 60%. Even though they are half-ceramic, these composites can display a relatively high fracture toughness, coupled with significant R-curve behaviour [16,17]. These results motivated the present study, which aims to show with clarity the ''metallic'' fracture behaviour of these half-metal/halfceramic materials by direct observation of crack-tip plastic zone dimensions.…”

“…The uniaxial stress-strain flow curves of the composites for which crack-tip strain fields were computed have been published elsewhere [17,42,45]. These curves were then fitted with the Ramberg-Osgood equation:…”

“…For Al-Cu2% alloy matrix composites, a solution heat-treatment was performed prior to fracture testing in order to dissolve intermetallic second-phases formed during solidification at ceramic/metal interfaces, which were found to affect the fracture properties of the composites [17]. Fracture tests were conducted on solutionised (T4) specimens.…”