Microwave Melting Of Tin Alloy Powder And Its Characteristics

As a keynonferrous metal indispensable to modern industry,Tin is widely applied in electronic information,industry ofchemicals,metallurgy,machinery,food packaging and others.At present,centrifugal atomization is an important approach for the preparation of tin alloy powder.A large number of ultrafine powders will be produced during the preparation of tin alloy powder byhigh speed centrifugal atomization.The traditional recovery method of these powders is to melt tin ingot through a resistance furnace,then quickly add Tin alloy powdersinto molten tin liquid and finally form the mixture of Tin alloy powder and melt after stirring and heating.After that,the mixture is then returned to the melting process of tin and recasted for usingafter remelting.This recovery process is complex,and the production efficiency is relatively low.In the process of multiple remelting,the energy consumption and labor cost are also greatly increased.Microwave melting characterized by the fast heating speed,high energy utilization,high heating efficiency,safety and no pollution.In the field of material preparation,it has become an important technical way to prepare high quality and new materials,especially in the preparation of powder metallurgy materials.In this paper,the author proposes that the microwave melting is adopted to heat industrial Tin alloy powder and carries out the study on mechanism of microwave heating of metal Tin alloy powder,melting features of it in microwave field and its industrial practice.The following conclusions are drawn:?1?Based on the analysis of materials features,the mechanic study of microwave heating metal Tin alloy powder has been conducted so as to analyze characteristics and melting kinetics of Tin alloy powder.It turns out that microwave melting has a better heating effect on tin alloy powder and is an efficient melting method.The way of material migration in the sintering process is consistent with the viscous flow mechanism,that is,during the melting process of the Tin alloy powder particles under the microwave,a viscous flow occurs on the surface of the particles to achieve the migration of material.?2?The temperature-rising curve of microwave melting Tin alloy powder has been quantitatively described with its heating rate nearly 122.4?per minute.The phase of analysis of sample gained in the melting has been measured with its density of 7.328g·cm^-3 and relative density around 99.19%.During the trail,and microstructure observations of elemental distribution is also measured.The elements and the tissue of alloy prepared by microwave melting distribute uniformly and have good compactness.This can effectively solve the problem of material returning during the centrifugal atomization preparation process of silver brazing powder that the energy consumption of microwave melting tin powder unit is only about 21%of the energy consumption of the traditional heating recovery tin powder.,shorten 2/3 time and eventually realize the efficient use of the resources.?3?A new innovative method of continuously melting tin alloys by microwave has been proposed.The pilot equipment is under development.And the continuous production line of microwave melting tin alloys has been established,using vertical furnace and adopting production method of micro-pressure?1.013×10⁵-1.2×10⁵Pa?overflow.It achieves continuous in-out melting way,that is,the upper feeding,the lower producing;The maximum treatment temperature is 600 with annual processing capacity of 2,000 tons.Tin-silver-cooper,tin-lead alloy and other alloys can all be melted in this way.