In recent years, dozens of options for body armor from a variety of materials have been created, each of which has its own strengths and weaknesses. One of them is the carbide of Bora, also known as the “black diamond”, named after its incredible strength and lightness, which makes it very attractive to the developers of body armor.
However, according to the Associate Professor of the Department of Materials Science and Engineering of Texas University Kelvin Ce, “Carbide Bora is effective for stopping bullets flying at a speed of less than 900 m/s, which corresponds to the combat capabilities of most pistols. At high speeds, carbide boron loses its protective characteristics “.
When exposed to boron carbide, the effect of the so -called phase transition arises from more powerful ammunition carbide, as a result of which the internal structure of the material changes – neatly located crystalline structures turn into glass -shaped loose mass, in which the atoms are randomly scattered.
“When the carbide of Bora is subjected to a phase transition, the vitreous phase creates the conditions for the spread of cracks,” continues. “Thus, any local damage caused by the blow of the bullet spreads freely throughout the material, causing even more damage.”.
Kelvin Ce and his colleagues from the University of Texas solved this problem, adding a little silicon to the carbide of Bora, which significantly increased its impact resistance.
To make sure of this, the team used diamond chips to simulate the effects of a high -speed bullet. After the experiment, scientists evaluated damage using an electron microscope. Result: Even with a small silicon additive, the updated material withstood the blows much more efficiently-scientists recorded a 30 percent decrease in phase transitions and, as a result, a decrease in the damage of the armor.
Source — Texas a & M University