The effect of heat treatment on microstructure evolution in artificially aged carbon nanotube/Al2024 composites synthesized by mechanical alloying

Journal Article · Sat Apr 15 04:00:00 EDT 2017 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2017.01.006· OSTI ID:22689733

Pérez-Bustamante, R. ^[1]; Pérez-Bustamante, F. ^[2]; Maldonado-Orozco, M. C. ^[3]

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1. Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No.120, C.P. 31109 Chihuahua, Chih. (Mexico)
2. Universidad Autónoma de Chihuahua (UACH), Facultad de Ciencias Químicas, Circuito No. 1 Nuevo Campus Universitario, C.P. 31125 Chihuahua, Chih. (Mexico)
3. Universidad Autónoma de Chihuahua (UACH), Facultad de Ingeniería, Circuito No. 1 Nuevo Campus Universitario, C.P. 31125 Chihuahua, Chih. (Mexico)

Although carbon nanotubes/aluminum (CNT/Al) composites are promising materials in the production of structural components, their mechanical behavior under overaging conditions has not been considered. In this paper the effect of CNTs on the microstructural and mechanical behavior of a 2024 aluminum alloy (Al2024) synthesized by mechanical alloying (MA) and powder metallurgy routes is discussed, as well as the effect of aging heat treatments at different temperatures and aging times. The mechanical behavior of composites was screened by hardness measurements as function of aging time. After 96 h of aging time, composites showed mechanical stability in their hardness performance. Images from transmission electron microscopy showed that the mechanical stability of composites was due to a homogeneous dispersion of CNTs in the aluminum matrix and a subsequent alteration in the kinetics of precipitation is due to their presence in the aluminum matrix. Even though strengthening precipitation took place during aging, this was not the main strengthening mechanism observed in composites. - Highlights: • Dispersion of carbon nanotubes during mechanical alloying • Microstructural evolution observed by HRTEM. • Mechanical performance evaluated through micro-hardness test. • Increased mechanical performance at high working temperatures • Acceleration of kinetics of precipitation due to CNTs, and milling conditions.

• OSTI ID: 22689733
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 126; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGING
ALUMINIUM
ALUMINIUM ALLOYS
CARBON NANOTUBES
DISPERSIONS
HARDNESS
HEAT TREATMENTS
IMAGES
KINETICS
MATRICES
METALLURGICAL EFFECTS
MICROSTRUCTURE
MILLING
PERFORMANCE
POWDER METALLURGY
POWDERS
PRECIPITATION
STABILITY
TRANSMISSION ELECTRON MICROSCOPY