Mechanical properties of Al/Al[sub 2]O[sub 3] and Cu/Al[sub 2]O[sub 3] composites with interpenetrating networks

Journal Article · Sat Oct 15 00:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90531-2· OSTI ID:6887373

Knechtel, M; Prielipp, H; Claussen, N; Roedel, J ^[1]; Muellejans, H ^[2]

---

1. Technische Univ. Hamburg-Harburg (Germany). Advanced Ceramics Group
2. Max-Planck-Inst., Stuttgart (Germany). Inst. for Metals Research

The rising fracture resistance with crack length in metal-toughened ceramics due to ductile bridging has been discussed from some selected microstructures and metal-ceramic combinations. An intriguing feature of these composites is the influence of interfacial fracture strength. Strong interfacial bonding leads to high geometrical constraint for the metal and high degree of triaxial tension in the metal ligament, thereby increasing the uniaxial yield strength by a factor of 5--7. This in turn increases the closure stress of the metal ligament, but ultimately limits the total plastic dissipation in the ductile reinforcement. The intent of this paper is to provide some insight on the influence of metal ligament size on both fracture toughness and fracture strength. The materials chosen are Al/Al[sub 2]O[sub 3] and Cu/Al[sub 2]O[sub 3] composites, both prepared by gas-pressure metal-infiltration of porous alumina preforms. SEM observations of fracture surfaces in conjunction with preliminary TEM and PEELS investigations of the metal-ceramic interfaces are used to explain the trends in mechanical property data.

• OSTI ID: 6887373
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 31:8; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MECHANICAL PROPERTIES
ALUMINIUM OXIDES
COMPOSITE MATERIALS
COPPER ALLOYS
ENERGY-LOSS SPECTROSCOPY
INTERFACES
SCANNING ELECTRON MICROSCOPY
TRANSMISSION ELECTRON MICROSCOPY
ALLOYS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
MATERIALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
SPECTROSCOPY
360603* - Materials- Properties