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Abstract:
A consolidation of powders using the KOBO method at elevated temperature was elaborated for production of Al/SiC metal matrix composite (MMC). The observations of the mean strain and inelastic strain range during the force controlled high cycle fatigue (HCF) tests identified the ratcheting mechanism combined with mechanism characterized by cyclic plasticity. Damage parameters were calculated on the basis of strain signal acquisition during fatigue tests. Fatigue properties, creep resistance and life time of Al/SiC MMC were gradually improved with the increase of the SiC particles content. The microstructural observations of the material before and after tests were also performed.

Keywords:
MMC, KOBO method, fatigue, creep, monotonic loading, microstructure, damage

Abstract:
Fatigue tests and microstructural observations were carried out to perform damage analysis of Al/SiC and AlMg/SiC metal matrix composites ( MMCs ). The materials were manufactured using a KoBo method. Ratcheting was the dominant damage mechanism for Al/SiC and damage parameter on the basis of mean inelastic strain was calculated. For AlMg/SiC, in most cases, cyclic softening followed by hardening during subsequent cycles were noticed. Microstructural observations identified existence of SiC concentrations which influenced the volumetric fraction of defects after fatigue tests

Keywords:
metal matrix composites, fatigue damage, microstructure, KoBo method

Abstract:
Creep tests under a range of step-increasing tensile stresses were carried out on the AlMg/SiC composites produced by means of the KOBO method. The content of reinforced phase was equal to 2.5, 5, 7.5 and 10%. The AlMg/SiC creep characteristics were compared to those of the Al/SiC composites. Structural assessments of materials in the as-received state and after creep were carried out.

Keywords:
metal-ceramic composites, KOBO method, creep, silicon carbide (SiC)