Study On Wear Mechanism Of Extrusion Container And Its Influencing Factors

Extrusion technology is widely used in aerospace,automotive,high-speed rail,military,electrical and other fields due to its high production efficiency and billet utilization ratio,good product quality and easy automation.As an important part of extrusion presses,extrusion container plays an important role in extrusion industry.Extrusion container usually works in a high temperature environment of 500℃,and at the same time,there will generate a huge unit pressure between inner of container and surface billet.During the relative sliding,the intense friction between the surface of the billet and the inner of the extrusion tube occurs.During the extrusion process,such contact is repeated,causing wear on the inner of the extrusion container.The wear of the inner of the extrusion container not only affects the quality of the product,but also affects the service life of the extrusion container.Therefore,it is necessary to study the friction and wear properties of extrusion container.With the development of computer technology,numerical simulation is more and more widely used in engineering practice,especially in the field of friction and wear.In this research,the inner wear of extrusion container under working conditions is simulated to provide methodological support for improving the friction and wear performance of the extrusion container.(1)The ball-plate experiments used a 4-level full-factor scheme with loads ranging is 60 N,90N,120 N,150N and rotate speeds ranging is 100r/min,300r/min,500r/min,700 r/min.The experimental results show that the friction coefficient decreases first and then increases with the increase of the load,and the relationship with the speed is not obvious.The wear rate increases with the increase of the load,which shows a linear relationship.Finally,the relationship between wear rate and load and rotate speed is fitted to provide reference for the determination of parameters in subsequent simulation.(2)Archard model was programmed into user subroutine by FORTRAN language,and the wear condition of extrusion container used in actual production was numerically analyzed by means of finite element method,with radial dimension reduction as wear value.In order to facilitate the calculation using a 2D model.Firstly,the interference assembly of the extrusion container is carried out.Under adiabatic condition,the wear of the inner of the extrusion container is simulated after 10000 cycles.The influence of sliding speed,friction coefficient,yield strength of billet and yield strength of extrusion container on wear is investigated.The wear amount increases with the increase of friction coefficient and yield strength of billet,and the wear amount decreases with the increase of yield strength of extrusion container.Because the influence of sliding speed on wear is mainly reflected in changing the temperature of contact surface and simulating wear under adiabatic condition,the influence of sliding speed is not obvious.(3)Based on the Taguchi method,the orthogonal experiment design is applied to the wear factors under the multi-factor coupling.Using the finite element software ABAQUS,the effects of different combinations of billet yield strength,H13 yield strength and friction coefficient on the wear of the extrusion container were studied,and the optimal combination with the minimum wear was found..