Characterization of Microwave Assisted Melting of Metals

Although metals do not normally absorb microwave, it has been shown that certain forms of metals can be heated using microwave. In this work, the heating and melting of metals such as lead , aluminum and copper using microwave is characterized. Microwave absorbing materials were used to assist the heating process. In situ temperature measurements show that the heating rate is very high and is temperature dependent. The dependence of heating rate on the power level and the load was measured. Up to 750 C, the heating rate is a linear function of temperature. Beyond 750 C, the heating rate decreases with temperature. Based on the dependence of dielectric loss of different materials, a suitable combination of susceptor material is proposed so that a high heating rate can be obtained at all temperatures. The microwave heating is also four times more energy efficient compared to conventional heating and methods to improve the efficiency further are also discussed