Experimental Investigation Of The Effect On The Emissivity From Surface Oxide Film Of Red Brass And Aluminum

Emission rate is the ratio of the radiating capacity of black body radiation and the object at the same temperature,which is also called Emissivity.It represents an important object of the basic characteristics of an object and is the characterization of the surface of the important parameters,especially in the rapid development of infrared measurement technology in recent years.However,emission rate is related to a number of factors.Such as: measuring the temperature of the material composition,environmental factors,metal surface oxidation,etc.This will make it difficult to accurately measure emission rate.With the rapid development of infrared temperature measurement technology in recent decades,the requirement for emission rate is also increasing.Scientists have made a lot of measurement methods and designed a lot of measuring instruments,but until now there is no experimental instrument that can be used as the main instrument for measuring the emissivity.And because of this comprehensive understanding of the emissivity is particularly important.This paper use specialized test instruments to measure some of the emission rate of common metal samples and experimental data on the emission rates of explanation and illustration,highlighting the surface oxide emission substances ratio.This is why my main research work during graduate.It also provides some advise for the industrial production.Metal has an important military role in daily life and industrial production.With the improvement of technology,they more and more pay attention to the quality of the metal material.It is necessary to take notice of control the temperature in the metal production process,because most metals requires high temperatures in the production process,such as extrusion,hot rolling and forging.In order to accurately measure the temperature of obtaining,it need to improve the accuracy of emission rate.This requires emission rate have a full understanding.This paper discusses the experimental apparatus and method for measuring the emission material.It is introduced the method of infrared temperature measurement that is,non-contact temperature measurement method in the second chapter.We can understand some of the advantages compared to conventional temperature measurement.And later this paper will elaborate infrared radiation theory and emissivity in detail,and has proved the fact in open a small hole in the closed cavity black body radiation,but also made a brief introduction on some of the basic theories.This article also made a detailed introduction on influencing factor of emissivity.It is mainly from the material itself,temperature,surface conditions,environmental measurements,and surface oxidation emissivity to discuss the influence of emissivity.Secondly,this chapter also made a detailed introduction on the emissivity measurement instrument.This instrument is based on energy law and Kirchhoff’s law theoretical basis,which focuses on the components of the instrument and the basic principles,as well as compared to the Some other advantages of the instrument.And they use this device for measuring the emission rate of a few groups of common metals and illustrate data.According to experimental data,we analyzed the relationship between temperature and spectral emissivity and surface oxidation.We can get at a given temperature emissivity expression and function of the heating time by concordant injection.we can clearly see the relationship.In this article,this paper introduce the material is to measure the rate of emission test equipment based on energy law and Kirchhoff’s law theoretical basis and by this means to study the emission rate of aluminum 3A21 material surface oxide,copper T2,relationship.In the experiment,the surface temperature is measured by an infrared detector.The radiation from the material sample surface and the black body cavity is received by the photodiode detector.It can measure temperature from 800k-1100 k of emissivity.When the experiment is carried out,the material in the air is heated to control the temperature of the experiment,it remains the same,the relationship between the observed spectral emissivity and heating time,through the analysis of experimental data obtained with the surface oxide emission rate relationships;It can also be drawn from the data at the same time heating the case emission rate and heating temperature relationship.Material in the process of heating in the air,the surface oxide film is formed gradually so that the rate of change in emission.As can be seen from the results,especially in the initial heating,the most rapid oxidation,the experimental results at this time are discussed and analyzed by fitting the experimental results obtained as a function of temperature and emissivity expression from the results can also be seen that the resonance peak emission rate of industrial production which provides some help.