Design Of Co-Re Chemical Vapor Deposition Equipment And Control System

Rhenium?Re?and its alloys are widely used in the fields of national defense,aerospace,electronics and petrochemical industry due to their excellent properties of high temperature mechanics,thermal fatigue resistance,wear resistance,corrosion resistance and catalysis.Cobalt?Co?is added to refractory metal Re to form Co-Re alloy,which can effectively improve the oxidation resistance of materials,expand the application range of Re coating in high temperature environment,and reduce the cost of preparing Re coating.In order to develop low temperature?<600??,low cost and environmentally friendly chemical vapor deposition?CVD?technology of rhenium alloy layer,two sublimation chambers were used,with Co?acac?₂ and Re₂?CO?₁₀0 as precursors,respectively,and the carrier gas H₂ was transported to the reaction chamber.Co atoms and Re atoms were deposited simultaneously on the barrel steel matrix of rapid-fire weapon?0CrNi2MoVA?to form Co-Re alloy anti-ablation coating.Calculating the size of sublimation chamber and reaction chamber by Dalton's law of partial pressure.The three-dimensional numerical simulation of the reaction chamber of Co-Re chemical vapor deposition equipment was carried out by CFD method.The effects of inlet shape,position,flow rate and pressure on the flow field near the base were studied in order to analyze whether the velocity field near the base was uniform.The mechanical part and control part of Co-Re chemical vapor deposition equipment are designed and selected.The conclusions are as follows:1)Co-Re chemical vapor deposition equipment consists of five parts:sublimation chamber,reaction chamber,gas transportation system,temperature system and vacuum system,and the mechanical parts of the equipment are designed separately.Based on Dalton's partial pressure law,the dimensions of sublimation chamber and reaction chamber are calculated as 50×200 mm and 30×200 mm,respectively.2)CFD simulation software was used to simulate the reactor of the equipment.The effects of different inlet shape,base position,inlet flow rate and chamber pressure on the velocity field near the base were discussed.The simulation results show that the velocity field near the base is more uniform and the pressure is larger when the straight nozzle,the base distance from the inlet position is 150 mm and the flow rate is 150 ml/min.Small has no obvious effect on the change of velocity field.3)Design the control system of Co-Re chemical vapor deposition equipment,including pressure control,flow control and temperature control,and select the control instrument;Flow control includes hydrogen compensation control in reaction chamber,and calculate the hydrogen compensation amount of 83ml/min in reaction process;Establish the mathematical model of pressure control and temperature control in reaction chamber of Co-Re chemical vapor deposition equipment.4)Co-Re chemical vapor deposition equipment was fabricated and tested.The experimental results show that Co-Re alloy coatings with uniform surface and compact structure can be prepared.