Fabrication and characteristic of Al-based hybrid composite reinforced with tungsten oxide particle and aluminum borate whisker by squeeze casting

Progress in research on hybrid metal matrix composites

It is a tough issue to design and fabricate discontinuously reinforced metal matrix composites (DRMMCs) with desired mechanical and physical properties. Utilizing nanocarbon materials such as one-dimensional (1D) carbon nanotubes (CNTs), two-dimensional (2D) graphene or their hybrids as reinforcements for DRMMCs is now considered to be a good solution because of their outstanding intrinsic characterizations. In this work, we proposed a novel in-situ space-confined strategy to circumvent the problem of the controllable interconnection and bonding between CNTs and graphene and thus constructed a well-dispersed CNTs embedded in three-dimensional graphene network (3D GN) hybrid structure for fabricating reinforced Cu matrix nanocomposites. The as-obtained 3D GN/CNT hybrids reinforced copper bulk nanocomposites exhibited a significant strengthening efficiency and a more balanced strength vs. ductility relation compared with Cu matrix composites reinforced by single component (CNT or 3D GN) with the same volume fraction.

In-situ space-confined synthesis of well-dispersed three-dimensional graphene/carbon nanotube hybrid reinforced copper nanocomposites with balanced strength and ductility

Effects of stirring parameters on microstructure and tensile properties of (ABOw+SiCp)/6061Al composites fabricated by semi-solid stirring technique

In this research work 6351 Al alloy based hybrid composites were developed in order to get improved properties of cast 6351 Al. On ex situ incorporation of SiC and Al2O3 through stir casting at 760 °C, a hybrid 6351 Al–(SiC+Al2O3) composite has been developed that exhibited massive segregation of particles and marginal improvement in strength and ductility with respect to cast 6351 Al. However, addition of fine TiC resulted in the generation of round shaped Al4SiC4 particles and when TiC and SiC were incorporated together in 6351 Al through stir casting, a novel hybrid composite consisting of in situ Al4SiC4 and ex situ SiC reinforcements in 6351 Al matrix was developed. Both the reinforcements were found to act as the nucleation sites for primary α (causing extensive grain refinement) along with the evident engulfment effects promoting uniform particle distribution. Furthermore, Al3Ti precipitates of nano-size evolved in the microstructure. Accordingly, the 6351 Al-(4 vol% TiC+4 vol% SiC) added composite exhibited a reasonable combination of strength (UTS=205 MPa) and ductility (%elongation=12).

K.H. Oh

Papers

Short-fiber/particle hybrid reinforcement: Effects on fracture toughness and fatigue crack growth of metal matrix composites