In this work, a reaction coupling self-propagating high-temperature synthesis (RC-SHS) method was developed for the in situ controlled synthesis of novel, high activity TiB2/(TiB2-TiN) hierarchical/heterostructured nanocomposites using TiO2, Mg, B2O3, KBH4 and NH4NO3 as raw materials. The as-synthesized samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM)...

The element of Fe can enhance the strength of TiB2/TiAl composite, but it is detrimental to the ductility of the composite due to the existence of large bulk TiB2 phase at grain boundary. The element of Mn is beneficial to the ductility of TiB2/TiAl composite, of which the fracture strain increases from 15.9 to 17.9 % with the addition of 2 at.% Mn. The element of Co can improve the strength an...

In situ synthesized TiB2-reinforced TiAl composites usually possess high strength. However, it is very expensive to use B powder to synthesize TiB2 particles. Moreover, the strength enhancement of TiB2/TiAl composite is generally at the cost of plasticity. In this study, in situ dual reinforcement TiB2-Ti2AlC/TiAl composites were fabricated by using B4C powder as the B and C source, which great...

It is reported that the ductility and strength of a metal matrix composite could be concurrently improved if the reinforcing particles were of the size of nanometers and distributed uniformly. In this paper, we revealed that gas atomization solidification could effectively disperse TiB2 nanoparticles in the Al alloy matrix due to its fast cooling rate and the coherent orientation relationship b...

The synthesis of AlN and TiB2 by spark plasma sintering (SPS) and the effect of Nb2O5, Y2O3 and ZrO2 additions on the mechanical properties and densification of the produced composites is reported and discussed. After the SPS process, dense AlN and TiB2 composites with Nb2O5, Y2O3 and ZrO2 were successfully prepared. X-ray diffraction analysis showed that in the AlN composites, the addition of ...

In this experimental study, three TiB2/Al metal matrix composites (MMCs) with 40 μm in mean size were produced using a melt stirring squeeze casting route. Test was carried out to find the parameters influencing surface roughness (Ra) and material removal rate (MRR) on machining the TiB2 reinforced Al-6063 composite materials. The orthogonal array, the signal-to-noise ratio, and analysis of var...

Bulk Cu-Ti alloy reinforced by TiB2 nano particles was prepared using in-situ reaction between Cu3.4wt.% Ti and Cu-0.7wt.% B along with rapid solidification and subsequent heat treatment for 1-10 hrs at 900oC. High-resolution transmission electron microscopy (HRTEM) characterization showed that primary TiB2 nano particles and TiB whiskers were formed by in-situ reaction between Ti and B in the ...

Nanostructured TiN/TiB2/Fe–Cr–Ni composite powder has been prepared via high energy ball milling. Ti and BN powders are reacted to form uniform mixture of TiN and TiB2 within 2 h of milling by a mechanically activated self-sustaining reaction (MSR). The crystallite sizes of TiN nd TiB2 are about 7 and 16 nm, respectively, after 32 h of milling. Through liquid phase sintering and optimizing the ...

The physical, mechanical, and thermal properties of polycrystalline TiB2 are examined with an emphasis on the significant dependence of the properties on the density and grain size of the material specimens. Using trend analysis, property relations, and interpolation methods, a coherent set of trend values for the properties of polycrystalline TiB2 is determined for a mass fraction of TiB2 ⩾ 98...

Using resonance ultrasound spectroscopy, we measured the monocrystal elastic-stiffness coefficients, the Voigt C ij, of TiB2. With hexagonal symmetry, TiB2 exhibits five independent C ij: C 11, C 33, C 44, C 12, C 13. Using Voigt-Reuss-Hill averaging, we converted these monocrystal values to quasiisotropic (polycrystal) elastic stiffnesses. Briefly, we comment on effects of voids. From the C ij...