In situ Al₃Ti/Al composites fabricated by high shear technology: microstructure and mechanical properties

Abstract

In situ Al3Ti/Al composites were produced by the reaction between Ti powder and Al melt with high shear technology. As Ti powder is starting material, it is important to investigate its size effect on the microstructure and mechanical properties of Al3Ti/Al composites. The results indicate that the necessary reaction time increases with increasing Ti particle diameter, which results in the Al3Ti phase coarsening. Particle sedimentation occurs at a short mixing time applying large Ti powder. Due to the presence of stiff Al3Ti particles, Young's modulus increases with particle volume fraction and fit well with the predicted values from the Halpin–Tsai equation. Moreover, together with grain refinement, these Al3Ti particles with a homogeneous distribution also lead to an increase in tensile strength.

In Situ Formation of Al3Ti and Its Effects on the Microstructure, Hardness and Tribological Properties of Al Matrix Composites with Various Ti Contents

“…Firstly, the introduction of Ti powders increases the plastic deformation of the Al matrix powders during the ball milling, which brings a more prominent work-hardening effect on the Al matrix powders [29,30]. In addition, the in situ formation of Al 3 Ti particles in the composite during the sintering process, especially fine Al 3 Ti particles in Al-10Ti, can increase the load-bearing ability of the composite upon indentation owing to the high Young's modulus and high hardness of the Al 3 Ti particles [19]. With the further increase of Ti content in the composite, the above mechanisms are further enhanced, and then Al-10Ti shows a much higher Vickers hardness at 331.2 HV, which is 234.9% and 131.1% higher than that of Al and Al-5Ti, respectively.…”

“…AMCs reinforced with particulate reinforcements, such as ceramic particles and intermetallic particles, have been broadly studied owing to their extraordinary mechanical and tribological properties [13][14][15][16]. Among the particulate reinforcements, Al 3 Ti has attracted much attention as a promising reinforcement in AMCs as a result of its high Young's modulus and high hardness, as well as its low density [17][18][19]. In particular, in situ formed Al 3 Ti particles can have a strong and robust interface with the Al matrix [20,21].…”

“…Zeng et al [19] prepared in situ Al 3 Ti/Al composites by using a high shear technology, during which the Ti powders reacted with the liquid Al matrix. Their results show that as the size of the Ti powders increases, the required reaction time increases, and relatively large Al 3 Ti phases are obtained.…”

Study on the Microstructure and Wear Behavior of In-Situ Al3Ti/Al Composites Under Induction Heating

“…Compared with ceramic particles, the Al-Ti intermetallic compound is used as the reinforcing phase of the aluminum matrix to eliminate the stress due to similar physical properties [2], and the wear resistance is improved obviously. Among them, in-situ formed Al3Ti particles have attracted increasing attention because of low density (3.4 g/cm 3 ), high hardness and strong wear resistance [3].…”

Synthesis and Characterization of In-Situ AA8011-TiB2 Composites Produced by Flux Assisted Synthesis

“…Likewise, the insitu titanium diboride was formed through the flux assisted technique with the aluminium as matrix and found the improved the mechanical strength, tribological strength and corrosion resistance [17][18][19]. Apart from TiB2, some of the most common insitu reinforcement synthesied through the flux assited technique are ZrB2, TiC, Al2O3, Al3Ti, and MgAl2O4 [20][21][22]. Though there are various techniques used to produce metal matrix composites such as casting technique, powder metallurgy [23,24], and diffusion technique [25] in the past, stir casting technique is mostly preferred owing to its simplicity, flexibility and cost-effectiveness [26].…”