Influence of Titanium Diboride Particle Size on Structure and Mechanical Properties of an Al-Mg Alloy

In the present study, aluminum alloys of the Al-Mg system with titanium diboride particles of different size distribution were obtained. The introduction of particles in the alloy was carried out using master alloys obtained through self-propagating high-temperature synthesis (SHS) process. The master alloys consisted of the intermetallic matrix Al-Ti with distributed TiB2 particles. The master alloys with TiB2 particles of different size distribution were introduced in the melt with simultaneous ultrasonic treatment, which allowed the grain refining of the aluminum alloy during subsequent solidification. It was found that the introduction of micro- and nanoparticles TiB2 increased the yield strength, tensile strength, and plasticity of as-cast aluminum alloys. After pass rolling the castings and subsequent annealing, the effect of the presence of particles on the increase of strength properties is much less felt, as compared with the initial alloy. The recrystallization of the structure after pass rolling and annealing was the major contributor to hardening that minimized the effect of dispersion hardening due to the low content of nanosized titanium diboride.Russian Science Foundation; The Research and Researchers for Industry (RRi) under the Thailand Research Fun

Ultrasonic Effect on the Penetration of the Metallic Melt into Submicron Particles and Their Agglomerates

Deagglomeration and wetting of submicron particles in a metal melt under ultrasonic exposure are considered based on the theory of acoustic cavitation and capillary phenomena. Basic dependences linking the exposure time with physicochemical properties of the particles and the melt, as well as with acoustic radiation characteristics, are found. The experimental and calculated times of ultrasonic treatment of the aluminum melt containing submicron aluminum oxide particles are compared, and a satisfactory agreement of results is found.This study was supported by the Ministry of Education and Science of the Russian Federation in the scope of the Federal Target Program “Research and Developments on Priority Developmental Directions of the Scientific-and-Production Complex of Russia for 2014–2020,” agreement no. 14.587.21.0019; the unique agreement identifier is RFMEFI58715X0019