Study On The Diffusion Behavior Of Al/Cu And The Vacuum Annealing Of Cold Rolled Fe Thin Film

The experiment and theory research of material characters and its variation under condition of high temperature and pressure in understanding astrophysics,universe,space technology,geophysics,strong load effects of materials,especially in energy projects,inertial confinement fusion and other basic science in modern times have an important theoretical and practical value.However,the state of high temperature and pressure is hard to gain.since high-power laser appears,the use of high-power laser can make materials achieve instant high temperature and pressure state,thus providing condition of laboratory research equation of state.Now the impedance matching method is most accurate and commonly used method to measure compression line of the material under condition of high temperature and pressure,thereby preparing high-quality impedance matching target is particularly critical.In order to reduce transit time measurement uncertainty,the initial density target should be close to the theoretical density of the crystalline material.The standard materials and material to be measured possess good surface quality and thickness consistency,the thickness of the interface layer is controlled within hundred nanometers,so that the vacuum diffusion bonding has become the best choice.This studied was prepared in experiments to provide the underlying physical data to prepare high-quality Al/Cu,Al/Fe and Fe/Fe target,successfully prepare Al/Cu impedance matching target.?1?Mirror pure Al hot pressure deformation experiments.Under the condition of heating temperature 450?,vacuum degree below 10^-44 Pa,holding time 1 h,the pressure force 3MPa,6 MPa,10 MPa and14 MPa,using white light confocal interference microscope accurately measured the thickness of the experiment sample before and after.The experiment showed that when the pressure force was 3 MPa,the thickness variation rate was 1.4%,while the pressure force was 6 MPa,the thickness variation rate was 2.3%.when the pressure was 10MPa,the thickness variation rate was 8%.With increasing of pressure force,the thickness variation rate increased.Under the condition of pressure force 4 MPa,holding time 1h,vacuum degree 10^-44 Pa,heating temperature 300?,350?,400?,450?,500?and550?.Using white light confocal interference microscopy accurately measured the thickness and surface quality of the experiment sample before and after.The sample were observed by optical microscope?OM?and scanning electron microscope?SEM?.The results show that as the temperature increased,the surface roughness of the sample was increased,the grain boundary became visible gradually,equiaxed grain size gradually increased.?2?Mirror Cu/Al vacuum diffusion bonding experiments.Using diffusion bonding process parameters were as follows:Under the condition of pressure force 4MPa,holding time1 h,heating temperature 400?,450?,500?,550?,600?.Experimental results show that constant time 1 h,heating temperature 500?and above,the composite sample in the Al/Cu mirror interface layer delamination appears three different phases:CuAl₂??phase?,CuAl??₂ phase?,Cu₉Al₄??₂ phase?,the growth of the order was CuAl₂,Cu₉Al₄,CuAl.The heating temperature was lower than 500?,CuAl₂ was mainly generated.A new phase was to first contact to form solid solution,saturated solid solution generate intermetallic compound,after the intermetallic compound lateral growth at first,then longitudinal growth,to form a uniform connection interface layer.Copper side brown zone was aluminum solid solution in copper.When the temperature was lower than 550?,the thickness of the intermediate layer was increasing with increasing of heating temperature.Temperatures above550?,the increase rate was significantly greater than the thickness of the low temperature.Under the condition of pressure force 4MPa,heating temperature 500?,holding time 1,2,4,6 h.Experimental results show that with increasing of holding time the intermediate layer thickness increased,but the thickness rate of increase became smaller.At last,the use of rolled aluminum and copper film was bonded by vacuum diffusion,successfully prepared high-quality aluminum/copper target was used for impedance matching experiments.?3?Cold rolled Fe thin film Vacuum annealing.The experimental apparatus is also ultra-high vacuum diffusion welding machine.Under the condition of holding time1h,temperature 250?,300?,350?,400?,450?,500?,550?,600?,650?and700?,pressure force 8N/cm².Using white light confocal interference microscopy measured Fe film surface morphology and roughness,the tested samples were analyzed by X-ray diffraction.The experimental results show that as heating temperature increased,the film surface roughness became smaller and surface morphology changed smooth for the better.When the temperature was less than 500?,the grain-oriented of iron film have not changed.When the temperature was 550?,the grain-oriented iron film occured gradually with recrystallization beginning.When the temperature was 600?,the grain-oriented iron film has completely changed,recrystallization has been completed,equiaxed grain growth process.As the temperature increased,the grain size of the iron sub-film also will be larger.Cold rolled Fe thin film annealing.Under the condition of holding time 1h,vacuum degree 10^-44 Pa,heating temperature 350?,450?,500?,550?,600?,650?and700?.Experiment results show that when the temperature was less than 550?,grain-oriented iron film did not change.When the temperature was 600?,the grain orientation changed significantly.Description iron film then recrystallization phenomenon has occurred.Temperature from 350?to 500?,the grain size of the sub-sample increased with increasing of temperature.Temperature from 400 to 550?,the residual stress was gradually reduced height.Until annealing temperature was 550?,the residual stress of iron film basic disappeared,appearing fine equiaxed grain,the size was about 400 nm.