Pinoy scientists look into mechanical properties of stardust

Scientists from the Ateneo de Manila University looked into the mechanical properties of silicon carbide (SiC), a chemical compound abundant as stardust surrounding carbon-rich stars and found in certain kinds of meteorites. 

“Silicon carbide (SiC) is a ceramic material with excellent wear resistance and strong covalent bonds having similar properties to metal,” according to the study, noting the compound’s outstanding physical and electronic properties. 

“Moreover, SiC also has a wide bandgap, making it a suitable semiconductor,” the study added. “Some applications of SiC include ceramic crucibles and plates, semiconductor bases, and seals.” 

The insulative properties of SiC also make it a prime candidate for heat shielding in nuclear reactors and spaceships. 

But the scientists noted that while the increase in carbon content of  SiC also increases the elastic modulus, or the material’s stiffness, it decreases the material’s other properties like its tensile strength, yield strength, and  toughness, making it brittle. 

“It can be observed that increasing the carbon content makes the material more brittle,” the study read. 

“More specifically, increasing percent C (carbon) results in an increase in elastic modulus until 25 percent C, a decrease in tensile strength, yield strength, and toughness.” 

Further, the scientists said that SiC is expensive as it is artificially grown on Earth for large industrial quantities. 

“However, SiCs are expensive and difficult to manufacture since they require high sintering temperatures due to strong covalent binding energy,” the study read. 

The scientists also recommended further studies using actual SiC test samples. 

“This study offered initial insights into the increase of carbon impurities in pure silicon, the proponents would recommend conducting a separate study on the effects of other parameters such as the effects of mechanical properties at elevated temperatures,” the researchers said. — Vince Angelo Ferreras/BAP, GMA Integrated News