Development Of Selective Laser Melting Equipment And Research On Processing Technology Of Titanium Alloy

At present,the selective laser melting technology which can obtain the best forming precision and mechanical performance in metal additive manufacturing technologies is gaining more and more application in the field of aerospace,biomedicine and national defense.However,SLM equipment from foreign country need high operating and maintenance costs and the process parameters are not open for using,this is not beneficial to the research and application of the selective laser melting technology in our country.Therefore,this paper studies the advanced SLM equipment technology,focusing on the review and design of the equipment’s structure and composition.It analyzed and processed the key factors affecting the machining accuracy.The forming processing experiments are carried out based on the developed SLM equipment.The specific research contents are as follows:(1)This paper completes the overall design of the SLM equipment.Referring to the design and composition of the SLM equipment at home and abroad,this paper selects and designs the structure of each sub-system including the laser scanning system,powder delivery mechanism,gas purifying system,water cooling system and so on.It proposes an economic,functional solution to the hardware components of the SLM equipment.(2)This paper constructs a set of electrical control system and designs the electrical connection and control programs of the main hardware of the SLM equipment.The equipment realizes the function of fully automatic printing based on the programming of the embedded scripts.(3)This paper solves some key technical problems in the development and debugging process.It analyzes the influencing factors of the machining accuracy.A method is proposed to reduce the error of the powder feeding system.The principle error and different kinds of distortion of the laser scanning system are analyzed and corrected.After debugging and calibration of the SLM equipment,the processing accuracy is improved.(4)The 3D printing experiments of Ti6Al4V powder are carried out to explore the forming parameter window on the SLM equipment platform.The relationship between the width and height of the melt pool with the laser powder and the scanning speed was explored.The phenomenon of balling,powder exploration and scale pattern in the printing process are analyzed.The variation of the density of the printed samples is studied.It is found that the density can be over 98%when the energy density is between 180~270 J/mm~3.