Development Of Miniaturized Laser Cladding Deposition Equipment

Laser cladding metal deposition is one of the main research directions of additive manufacturing technology,and has broad application prospects in aerospace,military equipment and other fields.For laser cladding deposition of active metals such as titanium alloys,high-temperature oxidation at the time of forming should be avoided,and no(low)oxidation in the forming environment is required to protect the molten pool.Currently,laser cladding deposition forming equipments with protection capabilities of molten pool are not suitable for the frequent use of laboratory processes,because they are generally bulky and expensive,and will consume a large amount of inert gas and take a long time of gas replacement.It is especially necessary to design a set of miniaturized(low)oxygen-free laser cladding deposition forming device with forming control system.By comparing the effect of vacuum and gas replacement on the equipment caused by low oxygen and low water forming environment,a proposal was made to put the laser cladding head into the forming environment as a whole.The forming chamber was determined to be 0.8 m×0.8 m×1.3 m of the square structure.Then,finite element software was used to analyze the thickness of the forming chamber box,The 3 mm thick 304 stainless steel plate and 6 mm thick 6061 aluminum plate was used as the box material.The 2 mm thick hollow square tube was used as support frame and suspension frame to achieve miniaturized and lightweight forming chamber.The circulating purifier was designed,using molecular sieve dehydration and the deoxidation principle of the copper catalyst.The water and oxygen content of the forming chamber was reduced by the circulating purifier,and the requirement for low oxygen and low water can be achieved quickly,compared with the large-scale equipment.Providing inert gas to protect the environment for laser cladding deposition of active metals.The four-axis motion controller was used to integrate the motion execution part and the related control circuit.The hardware was designed to realize the control of the three-dimensional platform motion,laser and powder feeding.Using MFC to develop a matching process control software,the software has achieved CLI file format reading and motion control code generation,and can scan path optimization and adjust the process parameter.Finally,using the device for laser cladding titanium alloy deposition experiments,when the argon filling rate was 30 L/min,the oxygen content in the forming chamber needed 35 min to be reduced from the atmosphere to 0.00% VOL.The oxygen content was 0.148%,which was 55% lower than in the atmosphere and less than the oxygen content of the original powder.The tensile strength and yield strength of the formed parts was 1 178 MPa and 1 105 MPa,and the elongation was 5.1%.The hardness of the formed parts was increased from the base plate to the cladding layer,the hardness of the cladding layer was about 390 HV and the hardness of the base plate was about 370 HV.Indicating that the laser cladding deposition device developed in this study can produce high-performance molded parts.