Abstract
TiC-reinforced AZ91D magnesium alloy composites were synthesized through the in situ reaction between an AZ91D melt and Ti-C-Al preforms. The microstructural evolution characteristics and phase transformation were investigated at different melt reaction temperatures (1013, 1033, and 1053 K), with the aim of understanding the in situ formation mechanism of TiC particles from thermodynamic and kinetic perspectives. The results showed that the temperature played a critical role in determining the formation and morphology of TiC. Initially, only the Al3Ti phase was formed through the reaction between Ti and Al when the temperature was 1013 K. With the increase in the melt temperature, the A13Ti’s thermodynamic stability decreased, and dissolution and precipitation reactions occurred at higher temperatures (1033 and 1053 K, respectively), contributing to the formation of TiC particles. The formation of the TiC phase was attributed to two factors: Firstly, A13Ti as an intermediate product reacted with carbon and formed TiC with increasing temperature. Secondly, the in situ TiC reaction was promoted due to the increased reaction-driving force provided by the increasing temperature.
Highlights
Magnesium and its alloys are used in the aviation, spaceflight, and transport industries due to their low density, high specific stiffness and strength, good damping performance, large reserves, easy recovery, and strong anti-electromagnetic interference capability [1–3].Magnesium and its alloys are known as the “green engineering materials of the 21st century” [4]; their poor mechanical properties, low corrosion resistance, and wear resistance greatly restrict their further application
Ti increased further decreased owing to the decomposition reaction by C, while the size of with
The decomposition reaction of Al3 Ti started, and the in situ reaction of TiC occurred at 1033 K; The formation mechanism of TiC in the AZ91D magnesium alloy can be described as follows: When the formation of Al3 Ti and TiC as the reaction products is thermodynamically favored, the phase transformation driving force is promoted by the temperature
Summary
Magnesium and its alloys are used in the aviation, spaceflight, and transport industries due to their low density, high specific stiffness and strength, good damping performance, large reserves, easy recovery, and strong anti-electromagnetic interference capability [1–3]. TiC-reinforced magnesium matrix composites prepared via powder metallurgy exhibit improved mechanical properties, as well as corrosion, friction, and wear resistance [28,29]. Through the self-propagating high-temperature synthesis process, the prepared TiC-particle-reinforced materials exhibited an improved yield stress and an ultimate tensile strength of more than 10% and 18%, respectively, and ductility values increased by 30% [30,31]. The precipitation of nano-sized MgZn2 was enhanced via mechanical stirring with the ultrasonic treatment of the Mg-4Zn-0.5Ca alloy reinforced with Ti. The as-extruded composite exhibited the best performance, with a yield strength of 369.8 MPa, an ultimate tensile strength of 393.6 MPa, and an elongation of. SiC+TiC nanoparticles changed the Mg17 Al12 morphology from plate-like to lamellar, thereby enhancing the yield strength, tensile strength, and fracture toughness [38] These particles formed an in situ precipitation, improving the performance by refining the grain size of the magnesium alloy—especially the addition of rare-earth elements during in situ reactive infiltration [39,40]. The influence of different temperatures on the in situ formation and microstructural evolution of TiC was studied; the thermal conditions and kinetic formation process of the in situ TiC-reinforced magnesium matrix composites were investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
