Optimal Design Of The Structure Titanium Alloy/CrN System Based On Numerical Simulation

Erosion wear is one of the main forms of material failure and causes huge losses every year.PVD technology brings dawn to reduce buffer wear.A certain thickness of hard film is deposited on the surface of the workpiece to enhance the surface strength and reduce the erosion rate,but different coatings have different erosion resistance.How to predict the erosion resistance of coating materials has become a research hotspot.Numerical simulation technology is a good method to predict the performance of coatings instead of experiments.In this paper,ABAQUS simulation software is used to simulate the erosion simulation process of nitride coatings.The erosion response of coatings and the factors affecting the erosion response of coatings are studied.The ultimate goal is to design a coating structure with high toughness and impact resistance.The Cr N hard coating was prepared by plasma unbalanced magnetron sputtering equipment.The mechanical properties of the coating were measured with a G200 Nano Indenter.Surface morphology and pitting morphology were recorded using SEM and super depth of field microscope.The nitride coating is a brittle material,and its fracture principle is very complicated.It has high compressive capacity and low tensile capacity,that is,it can withstand high tensile stress,but cannot bear low amplitude tensile stress.After the coating material is subjected to erosion,a local tensile stress zone or a compressive stress zone will be generated inside,and failure will occur if the material’s yield limit is exceeded.The explicit dynamic module of ABAQUS simulation software is a dynamic shock analysis method.The stress field distribution and numerical value after the software post-processing are used to pre-analyze the mechanical properties of the coating material.In this paper,the simulation data and experimental detection of Cr N coatings/Ti6Al4 V system prepared under the substrate bias of-50 V and-100 V were compared.Secondly,the structure of Cr N coating on Ti6Al4 V soft matrix was optimized.The coating thickness and the coating modulus were used as the variables for simulation,and the optimal coating structure was selected.For Ti6Al4 V matrix,the optimal thickness range of Cr N thin coating is between 4 cm and 7 cm and the optimal modulus is around 250 GPa.According to this interval,the multi-layer structure of Cr N was designed.The multi-layer structure with a total thickness of 5.4 μm.A high/low modulus cycle of 8 cycles was selected and then compared with the high-modulus monolayer.Simulation results: compared with single-layer high modulus coating,the maximum tensile stress of the system was reduced by 1969 MPa because of the design of multi-layer plain coating.The maximum tensile stress value of the surface was reduced by 7412 MPa.Based on the analysis of morphology and mechanical properties,multi-layer Cr N has high toughness,hardness up to 23.7 GPa,and modulus up to 309.6 GPa.