Characterization of a hybrid Al₂O₃–aluminum matrix composite manufactured via composite extrusion

Abstract

The development of new metal matrix composites for lightweight applications is aiming for an increase in specific strength and stiffness compared to conventional light metal alloys. The composite extrusion process is a promising manufacturing method for continuously reinforced light metal profiles. Especially the reinforcement with ceramic fibers leads to an increase in the specific strength and stiffness. For these investigations a hybrid composite is produced by using an Al 2 O 3 -fiber/AlMg0.2 composite wire which is embedded in an EN AW-6082 aluminum matrix. It is shown that the mechanical properties of the composite exceed those of the unreinforced matrix material. An explicit investigation of the deformation and damage behavior of this composite is given by optical strain analysis and in situ tensile tests in an X-ray micro computed tomograph (m-CT). It was observed that during tensile loading multiple fracture of the composite wire occurs while exceeding the strain limit of the non-embedded composite wire. It could be shown that fracture of the composite wire is accompanied by strain localization and therefore strain hardening occurs in vicinity of the internal fracture, which leads to multiple necking of the specimen. The m-CT analysis reveals the intrinsic damage mechanisms and shows the beginning of ceramic fiber fracture which showed evidence for a local load distribution between the fibers resulting in a planar fracture of the composite wire. The multiple fracture of the wire allows for an interface shear strength analysis and indicates a good bonding of the composite wire.

Effect of matrix powder and reinforcement content on tribological behavior of particulate 6061Al-TiB2 composites

“…4,5 To overcome this drawback, 6061Al alloy is reinforced with hard particles to improve its tribological properties. The widely used particles for reinforcing aluminum-based composites are SiC, Al 2 O 3 , TiC, titanium-di-boride (TiB 2 ), and B 4 C. 2,6 These reinforcement particles act like a hard dispersoid in the matrix, which constrains plastic deformation under stress and improves mechanical properties. 7 Among the various reinforcements used in Al metal matrix composites, TiB 2 offers superior young modulus, stiffness, hardness, and conductivity as compared to other ceramic dispersoids.…”

Microstructure and properties of in situ Ti–Al intermetallic compound-reinforced Al matrix composites with dispersive distribution of core–shell-like structure

“…The weighted decision matrix is determined by multiplying the normalized decision matrix with corresponding weights. The weighted normalized value v ij is calculated using equation (9).…”

“…4 –6 Traditional ceramic particulates, including SiC, SiO 2 , B 4 C, TiB 2 , and Al 2 O 3 , are often used with pure aluminum or alloys to prepare AMCs. 7 –11 For these conventional AMCs, reinforced phases are prepared separately prior to composite fabrication and are limited by initial powder sizes and poor wettability between reinforcements and matrix. In order to overcome these key problems, in situ AMCs, in which reinforcements are synthesized in a metallic matrix by chemical reactions between elements or elements and compounds during composite fabrication, have attracted increasing attention from researchers.…”

Effect of the spark plasma sintering temperature on the microstructure and mechanical properties of a ceramic/metallic glass reinforced hybrid composite

“…12 Recent research trends are focused on hybrid composites as they have superior properties compared to non-hybrid composites. [13][14][15] The various reinforcing particles in hybrid composites synergize and complement each other to provide improved properties. Using the stir casting technique, Verma et al 16 have developed AA 7075 matrix hybrid composites containing B4C and Rice Husk Ash (RHA).…”