Phys.org April 22, 2024 Refractory alloys are very resistant to heat and wear but are not ductile or resistant to fracture. A team of researchers in the US (UC Berkeley, Lawrence Berkeley National Laboratory, UC Irvine, Pacific Northwest National Laboratory) examined the strength and fracture toughness of the Single-phase body-centered cubic (bcc) refractory alloy, NbTaTiHf, from 77 to 1473 kelvin. Whereas the glide and intersection of screw and mixed dislocations promoted strain hardening controlling uniform deformation, the coordinated slip of <111> edge dislocations with {110} and {112} glide planes prolonged nonuniform strain through formation of kink bands. These bands suppressed […]
Tag Archives: High temperature materials
Team uses 3D printing to strengthen a key material in aerospace, energy-generation applications
MIT News May 19, 2022 An international team of researchers (USA – MIT, Turkey) used additive manufacturing (AM) of a nickel superalloy metallic matrix composite (Ni-MMC) using laser powder bed fusion (LPBF). They prepared nanoceramic-containing composite powders by high-speed blender decluttering and ball milling of as-received SiC nanowires (2 vol%) and Inconel 718 alloy powders which produced a homogeneous decoration of SiC on the surfaces of Inconel particles. Analysing the as-printed specimens revealed the dissolution of SiC nanowires during laser melting, leading to the in-situ formation of Nb- and Ti-based silicide and carbide nanoparticles. The in-situ formed nanoparticles resulted in […]
Scientists develop the most heat-resistant material ever created
Phys.org May 27, 2020 Using the method of self-propagating high-temperature synthesis, an international team of researchers (Russia, USA – University of Notre Dame) fabricated nonstoichiometric hafnium carbonitrides (HfCxNy). It had a rock-salt crystal structure with a lattice parameter of 0.4606 nm. and hardness of 21.3 GPa. The melting point of this synthesized material was experimentally shown to be higher than that of binary hafnium carbide. The nonstoichiometric hafnium carbonitride was then consolidated under a constant pressure of 50 MPa at a temperature of 2000 °C and a dwelling time of 10 min, through spark plasma sintering. The obtained bulk ceramic […]