Synthesis of metal nitride by microwave irradiation

Abstract

The products from Ti and Al metal powder via 28 GHz-microwave irradiation in air were investigated. The high frequency microwave (28 GHz in this work) is known to inhibit the electric discharge between particles in contrast to the low frequency microwave (2.45 GHz, for example) which induces the discharge that causes melting and/or joining of particles. The product from Ti powder was α-type interstitial compound with nitrogen and oxygen, and the content of nitrogen increased more rapidly than that of oxygen with increasing the irradiation time. In the case of Al, however, the contents of nitrogen and oxygen did not change during irradiation even heated up to the near melting temperature.