Design Of Screw Rotor And Laser Selective Melt Forming Test

For the air compressor,the screw rotor is like the heart to the human,and it is the core component that determines the performance of the air compressor.At present,its processing methods are made of reduced materials.After passing through multiple machine tool stations,it also requires professional personnel to operate and supervise the equipment,which is tedious and time-consuming.The selective laser melting technology that has emerged in recent years is in line with the "green manufacturing" concept proposed in China's "Smart Manufacturing".It can directly use laser to melt metal powder to form complex metal parts.The cycle is short,no tooling fixture is required,and it has a high density.Therefore,this paper designs a screw rotor based on the principle of gear meshing,tries to use TC4 titanium alloy as the forming material,and uses the laser selective laser melting additive manufacturing method to experimentally shape it in order to explore another screw rotor.Processing methods,the main research work is as follows:(1)The data points of the female and male screw rotor end profile can be obtained by MTLAB software.In the UG 8.5 software,the air compressor screw female and male rotor models are established respectively.After assembly,they are checked for static and common interference.After no interference,the first six orders of modal analysis were performed in ANSYS software.It can be seen that there is no resonance phenomenon in its work.(2)Before the screw rotor is formed by SLM technology,the preliminary process planning is carried out,and the sample under the process parameters is analyzed by basic tests.It can be known that the sample density can be as high as 97%,the size error of X direction and Y direction is about +100?m;The structure of the sample in the deposited state is mainly ? and ?,the internal structure is relatively more uniform after annealing,and the structure performance is improved;the hardness of the longitudinal section of the sample is slightly higher than the cross section,and the overall average hardness decreases by about 3.14%,the main reason is that the hardness is slightly reduced due to the release of internal residual stress;the tensile strength and yield strength of the sample in the Z direction are slightly lower than the XY direction,but the end face in the Z direction shrinks.The elongation rate are higher than its XY direction,and the overall performance after annealing treatment is improved to meet the forging requirements.(3)According to the basic experimental analysis,comprehensive consideration is given to the placement of the screw rotor in the longitudinal direction.After forming,it is found that the male rotor structure is prone to cracks at the tooth top after annealing treatment.Theoretical analysis is due to the residual stress at the corner transition.The structure was verified using the finite element method,and the rotor with good quality was successfully formed by adjusting its scanning strategy,and the profile of the female and male rotors was tested.Although there are minor defects,the overall quality is good and can be meet rough grinding standards.