The Filling Technology Of Grooves In The Inner Wall Of Thrust Chamber And The Polishing Equipment

The thrust chamber is the core component of liquid rocket engine to produce propulsion force.Because of the bad working environment and the characteristics of structure,it puts forward very strict requirements for its manufacturing methods.Electroforming with unique characteristics is one of the technologies that can not be ignored to manufacture the thrust chamber,especially the high chamber pressure thrust chamber.However,there are still some technical defects to be solved urgently in the process of electroforming thrust chamber,such as the filling and de-filling techniques,which restricts the processing efficiency.Also,the traditional groove filling method has many shortcomings and conflicts with the pre-treatment.In addition,there is a lack of the corresponding equipment for the pre and post-treatment of large and medium-sized thrust chambers.Therefore,this paper carries out the research on the filling technology of grooves in the inner wall of thrust chamber and the development of the polishing equipment.（1）In order to explore a new filling and electroforming process,EPS foam with high de-filling efficiency is selected as the supporting material,and conductive layer based on gypsum matching EPS foam is explored.This paper expounds the reasons and advantages of EPS foam selection,quantifies the dissolving speed and dissolving quantity of limonene to EPS foam: the dissolving speed of limonene to EPS foam at room temperature is 0.75cm³/s,at 85℃is up to 5cm³ /s,and the dissolving quantity of per milliliter limonene to EPS foam is up to 229.82cm³.The volume ratio of each component in the conductive layer affects its resistivity,and the quality of the electroforming copper layer on the conductive layer is investigated by filling and electroforming straight channel.The results show that the inner surface of copper layer on the three conductive layers is rough and there are powder residues that are difficult to remove.（2）The behavior of electrodeposition copper on conducting polymer made from silver-cladding copper powder,nickel powder and conductive carbon before and after electrolytic treatment was studied.The results show that Cu²⁺ can nucleate successfully on the three conducting polymers before electrolytic treatment.The initial potential and polarization of conductive polymer made from nickel powder are the lowest,and the deposition energy of constant potential and constant current can enter the stable state as soon as possible.The electrodeposition behavior of copper on conducting polymer changed after electrolysis.Although there is Cu²⁺ still reduction,the equilibrium potentials at the twophase interface are all moving forward,and the conductive polymer made from silver-cladding copper powder has the largest shift,followed by the nickel.Compared with the other two kinds of conductive polymer,the effect of electrolysis on the conductive polymer made from silver-cladding copper powder is more significant.The electrodeposited layer has different growth morphology,which can be summarized as coral,scale and star point.（3）Integrated equipment and auxiliary equipment are developed to automatically fill,polish and turn the large and medium-sized thrust chamber.The design method is from top to bottom to determine the functional modules that the equipment system should have,and the basic requirements for each functional module are put forward.Then the key technical index parameters are established.The overall scheme and the three-dimensional structure design of the main components are carried out with explaining the basis,ideas and important dimensions one by one,and the general layout with the designated laboratory setting as the installation site is provided.