Design And Manufacture Of Photo-electric Measuring Instrument For Superplastic Free Bulge

Structure superplastic materials is good at low strain pressure,well plasticity,little induration shape easily,high precision,no reverberate and well soid viscidity and sound insulation in state of superplasticity .superplastic formation technology and processing is simply,which can shape complicated sheet and union in one part,strength intention and take weight. Superplastic bulge is a processing that work in gas pressure ,which is a low powe and low pressure superplastic technology .Because superplasticity is effect by stain rate, flow stress of superplastic materials is low ,the the forming pressure is low,which is a advantage for sheet, then the processing of superplastic bulge of sheet is intensively used in aerospace aviation, vehical, electronics instrument, home appliance, and other industry field.Superplastic bulging is a important processing of superplastic formatting, which take key role in mechanical of superplastic research and application. superplastic free bulge is in two dimension strain state, no rub influence, boundary condition is knowned family and the pressure of forming is controlled. Take superplastic mechanical research is not convenient way but also a good example. In theoretical view ,it is a inevitable way from one dimension to three dimension ; in application view, SPF and SPF/DB union processing have take place a great advantage, which is intensively used in aerospace, car, electronic appliance and etc. Research of superplastic bulging have great significance in theories and application. The research and development of superplastic bulge experience instrument take a key role in development of theory and experiment of bulge, also have important function for development of superplastic technology.Because in superplastic state, the forming pressure of materials is very low, which is sensitivity to temperature .sample of superpastic bulge have to closed in press bucket. The experiment process of bulge is control by P-t and p-h curve in experiment only, the bulge pressure and relation of apex H and t can not directly measure and record, so it is can not get accurate experiment date. It is a problem that research bulge mechanical theories.My tutor Song Yuquan professor engage in researching of superplasticity many years, the research and development of experiment instrument of superplastic bulge had own advantage and special features. Many years ago ,he had development 'light and electricity measure experiment instrument of superplastic bulge', which adopted no contact measure method to measure and record the changes of apex of superplastic bulge with time. Because calefaction is used by round electric resistance ,the temperature is up slowly ,and can not remove the effect of change of electromagnetism filed, the problem of back pressure and oxide in high temperature is not resolve completely.In 2004 ,my tutor had invention patent of superplastic bulge device ,which can purify the Ar gas, heat outside the furnace ,temperature and pressure can auto control ,can exert back pressure, and work in different route, include constant press bulge, constant velocity bulging ,constant apex stain rate bulging, to carry on experiment ,at the same time , can record the changing figure of sample of superplastic bulging in experiment.So , according to the patent , I development a instrument of superplastic bulging, which can clear up the Ar gas, which heated outside the furnace ,temperature and pressure can auto control , can exert back pressure, and work in different route, include constant press bulge, constant velocity bulging ,constant apex stain rate bulging, to carry on experiment ,at the same time , can record the changing figure of sample of superplastic bulging in experiment. The main contents is following. 1.desige of superplastic bulging, including reclaim the liquid presses machine; design the press side bucket and furnace, adoption Ar gas as medium to superplastic bulging, including up and down enter gas system,for back pressure and pressure; at the meantime, can heat the gas and auto control pressure of working gas. 2.development of light-electricity record system, the problem of that can not measure the chang of apex high directly is resolved by non-contact ligh-electricity measure system, which is a invention . According to the patent, this thesis will take place originally of adoption light battery conduct and actions exposed to light the component improvement as adoption digital camera, record the whole bulge form process with the digital camera, and by processing digital picture and related calculation , get arbitrarily and every moment H(t) and related information of the bulge form apex height.The low controller core that compound by personal computer and single controller carry on measuring and control to the superplastic form device, the main control PC mainly passes a digital camera to record experiment of process of the bulge processing, and carry on a related data a processing,low machine control the electric circuit mainly examines with the control experiment pressure, temperature…etc. In the meantime, core control PC and low machine control electric circuit to communicated by I/O of PC and interface developed by VC.