| Die plays an important role in industrial production.More than 50%of parts and components are completed with the help of die in the process of production and manufacturing.However,the working conditions of dies are relatively harsh.They have to withstand severe friction,high temperature and pressure,impact loads and other effects during use,which can easily lead to problems such as thermal fatigue,deformation and even cracking.Considering that most of die failures start from the surface,surface modification can improve surface performance and prolong service life of the die.This not only improves product quality,but also saves costs,effectively utilizes resources,and has significant economic benefits.As a surface treatment method,physical vapor deposition(PVD)has the advantages of low deposition temperature,environmentally friendly,pollution-free,easy to obtain coatings with high hardness and good wear-resistant.It has become one of the main technologies in modern surface processing.At present,the coating prepared by this method is mainly used in tool industry to improve the wear resistance of materials and gradually expanded to the field of dies.But the research on performance of die steel after deposition is not sufficient.H13 steel has the advantages of high hardness and wear resistance.It is widely used in the manufacture of various forging,die-casting and extrusion dies.Therefore,in this paper,TiAlSiN coatings were prepared on H13 steel by magnetron sputtering with bias voltage,deposition temperature and film thickness as variables.Firstly,the influence of sputtering parameters on the surface morphology and cross section morphology,element content and phase composition of coatings were investigated through SEM,EDS and XRD testing.Secondly,the nano-hardness,adhesion,wear resistance and corrosion resistance of coatings were studied through nanoindentation,scratch,frictional wear and electrochemical experiments.The influence rule of sputtering parameters on the coating performance was explored,and its mechanism of action was revealed.Finally,the finite element software ABAQUS was used to establish a numerical model of the residual stress generated during cooling process of the coating.Then the size and distribution of the residual stress were analyzed,the influence of sputtering parameters on residual stress was investigated,and the residual stress was calculated by X-ray diffraction method,which verified the reliability of the model.The main results are as follows:(1)With the increase of bias voltage,deposition temperature and film thickness,the number of particles on the surface of TiAlSiN coating decreases,and the film quality improves.Due to changes in sputtering parameters,atoms may migrate,causing slight fluctuations in the concentration of various elements in coatings.The sample is mainly composed of three phases:Fe,Ti3Al2N2 and TiN.At higher bias voltage,deposition temperature,and film thickness,the diffraction peaks of Ti3Al2N2 phase become wider.(2)The nano-hardness,adhesion,frictional wear performance and corrosion resistance of TiAlSiN coating were studied.It was found that bias voltage has a significant influence on the hardness of coatings.And film thickness has the most significant influence on the adhesion.When the bias voltage and film thickness increase,the wear resistance of coatings improves.In addition,when the surface of the coating is dense,the corrosion resistance of the coating is stronger because NaCl solution is difficult to penetrate into the substrate through surface defects.(3)The residual stress generated in TiAlSiN coating was simulated and calculated by ABAQUS software.It was found that the residual stress in the coating exists in the form of compressive stress,with the maximum stress located at the center of interface between the coating and the substrate.Due to incomplete consideration of the intrinsic stress caused by coating defects during modeling,the simulated value of residual stress is smaller than the calculated value. |
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