Preparation And Properties Of Ceramic Materials Microwave Thermal Effects

Microwave as a kind of clean energy, depending on the material dielectric characteristics itself changes microwave energy to generate heat, are now widely used in everyday life.However, the existing of oven cooking utensils made of ceramics, glass, plastic and metal etc. cannot absorb microwave, and some materials may release harmful substances to human body in the heating process; At the same time due to the appliance itself can only be transmitted microwave cannot absorb it, which can easy to heat food too fast causing overheating phenomenon, are produced accident in the microwave oven use frequently; Others used in microwave heating vessels for metal as the substrate through the built-in absorbing material or adhesive high temperature resistant rubber layer to absorb microwave fever, but due to the vessel base metal for microwave shielding effect lead to only a small amount of microwave absorption, low surface temperature, the thermal efficiency is not high, and the metal thermal conductivity coefficient is bigger, cannot have the effect of the heat storage for a long time. This paper in the traditional ceramic raw materials for ceramic body the main composition, by adding a certain proportion of Fe2O3as absorbing agent, at the same time by adding pore-forming agent material with porous ceramics in order to increase its regenerative properties. Combined with the traditional ceramic sintering process, the preparation of the both can absorb microwave and composite absorbing ceramic material with heat storage functions.In this paper, through the phase diagram analysis and exploratory experiment, confirmed the microwave thermal effect ceramics sintering system:first of all, at a rate of about3～5℃/min from room temperature to500℃, the heating preservation of60-90min; Then in1-2℃/min heating rate from500℃up to900℃, heat preservation2-3h, this phase is mainly is to guarantee the complete decomposition of calcium carbonate and exhaust gas pore; Finally in3-5℃/min heating rate slowly heat up to1350℃, the highest temperature insulation13-15h.Due to the material composition proportion, forming pressure and pressure maintaining time, pore-forming agent and sintering temperature has a great influence on the absorbing wave absorption performance of ceramic materials and heat storage performance, so this thesis focuses on the above factors on the absorbing wave absorption performance of ceramic materials and heat storage performance, the influence of the preparation of ceramic composite absorbing material for optimum process parameters for the material composition proportion is45%SiO2,22.5%A12O3,30%Fe2O3,2.5%gMgO,5%CaCO3, molding pressure to10mpa, the holding time is10min, the sintering temperature is1350℃. Under the condition of the process parameters, the preparation of the composite absorbing microwave ceramic materials, the temperature can be over170℃within3min in500w microwave heating field, the composite material from175℃to30min after natural cooling temperature is still higher than70℃.From material characterization of mechanical properties and dielectric properties analysis shows that under the condition of optimum process, the preparation of the composite absorbing microwave ceramic material of bending strength of77.2MPa. After5times of thermal shock cycles the compressive strength loss rate is about28%. Prepared by the microwave composite absorbing material with good bending properties, dielectric properties, can meet the needs of daily household microwave oven utensils.