Research On Microstructure And Mechanical Properties Of In625 Alloy Fabricated By Additive Manufacturing With Mechanical Vibration

As a typical rapid prototyping method,laser additive manufacturing technology can shape and manufacture high-performance complex metal parts.It has many advantages such as short design and manufacturing cycle,no need for cavity tools,and high controllability of the manufacturing process.It has been widely used.Aerospace,marine,medical,petrochemical and mold industries.Laser additive manufacturing is a complex micro-metallurgical process with multiple physical couplings.The dependence of its solidified structure on process parameters is uncertain.The extremely complex material metallurgical process is still not very clear.At present,there is still no effective method to accurately control the microstructure and mechanical properties of additive components.In order to achieve a higher degree of freedom in the control of additive manufacturing organization and performance,new methods for effectively regulating the laser additive manufacturing process are urgently needed to be developed.In this paper,the commonly used metal material In625 is a new type of rapid manufacturing method.Its principle is to use a high-energy laser beam to melt the metal powder at high temperature.The laser beam moves according to the path set on the computer software,and then bottom On the other hand,three-dimensional parts with complex shapes are formed.In625 superalloy is a commonly used metal material for experimental raw materials.By applying mechanical vibration in the process of laser additive manufacturing,the mechanism of the effect of mechanical vibration frequency and amplitude on the solidification structure and mechanical properties of laser additive manufacturing is studied,so as to provide a basis for mechanical vibration to assist in controlling the structure and performance of laser additive manufacturing components the study.The main research work is divided into the following aspects:In addition,the vertical mechanical vibration assisted laser additive is used to manufacture In625 superalloy.The macroscopic morphology and microstructure of In625 superalloy directly deposited by laser under different mechanical vibration parameters were characterized and analyzed by means of laser confocal microscope and optical microscope.The results show that the solidification behavior of the micro-melt pool produced by laser additive manufacturing is affected by mechanical vibration.With the increase of mechanical vibration frequency,the directional crystals grown in vertical orientation are suppressed and gradually transformed into small grown obliquely.The change of mechanical vibration amplitude can regulatethe crystal growth direction to a certain extent.At the same time,mechanical vibration helps to make the surface of the alloy sample smooth.The In625 superalloy sample manufactured by laser additive was cut and the surface was polished to prepare a tensile sample.The influence of auxiliary mechanical vibration on the mechanical properties(tensile properties and hardness)of the solidified structure of In625 superalloy was studied.The research results show that with the increase of mechanical vibration frequency,the hardness,yield strength and elongation of In625 superalloys tend to increase and then decrease.When the mechanical vibration frequency is 100 Hz,its hardness,yield strength and elongation have reached their maximum.With the increase of the amplitude of mechanical vibration,the hardness of In625 superalloy showed a downward trend,while the yield strength and elongation showed a downward trend.When the tensile mechanical properties of In625 alloy manufactured by laser additive are used as the evaluation standard,the best mechanical vibration parameters are: frequency 100 Hz,amplitude 0.25 mm.The solution heat treatment of In625 alloy manufactured by laser additive manufacturing was conducted to study the effect of different solution heat treatment temperature and mechanical vibration on the mechanical properties of In625.The research results show that the hardness of In625 superalloy decreases with increasing solid solution temperature.With the increase of solution temperature,the tensile strength of In625 superalloy increased first and then decreased.At 850℃,its tensile strength reached the highest level,which increased by 4.88% compared with the deposited state.As the solution temperature increases,the elongation of the In625 alloy gradually increases.At 1050℃,it is 26.67% higher than that in the as-deposited state.As the solution temperature increases,the yield strength of In625 alloy tends to decrease.In this paper,by studying mechanical vibration assisted laser additive manufacturing of In625 superalloy,it is shown that the application of mechanical vibration is an effective method to adjust the solidification structure and mechanical properties of laser additive manufacturing.By reasonably matching the mechanical vibration parameters and laser additive manufacturing parameters,the grains of the solidified structure can be refined to a certain extent,and the tensile mechanical properties of the solidified structure can be improved.The research results help to promote the development of laser additive manufacturing shape-shape integrated control technology.