Study On Microstructure And Wear Resistance Of Cu-Fe-Si Alloy Materials

This paper adopts the non-self-consuming vacuum arc melting Cu-Fe-Si alloy materials were prepared with the help of HSR-2M type high speed reciprocating friction and wear testing machine,analyzing the relationship of silicon content,friction load,friction speed,and friction coefficient with the method of single factor experiment,and analyzing the influence of the silicon content on the friction and wear properties and the mechanical behavior of copper alloy under ‘the ball-face’examination.The microstructure,phase structure and composition of the surface of the specimen and the dual friction pair were analyzed by scanning electron microscope(SEM),ultra-depth of field micro-system,energy spectrometer and X-ray diffractometer(XRD).Experimental results show that:(1)The compressive performance of Cu-Fe-Si alloy first increases and then decreases with the increase of silicon content.The yield strength of Cu-Fe-Si alloy is very high when the silicon content is 5%.With the increase of silicon content,the compressive strength of the material gradually improves.When the silicon content is13%,the compressive strength of the copper alloy reaches the maximum value of1168.58 mpa.As the silicon content continuous increase,the compressive strength of the material gradually decreases.(2)In Cu-Fe-Si alloy,when the silicon content is lower than 18wt%,all the silicon in the system can fully react with copper and iron to form metal silicide.The hardness,corrosion resistance and wear resistance of copper alloys can be improved by appropriate amount of metal silicide.At the same time,it can reduce the porosity of the structure,improve the surface finish,reduce the damage degree of the friction surface,and reduce the friction factor and wear rate of copper base alloy.(3)At the same speed,the higher the friction load,the lower the friction coefficient.Under the same load,there is a linear relationship between rotational speed and friction coefficient.At constant speed and load,with the increase of silicon content,the friction coefficient first decreases and then increases,and the volume wear rate first decreases and then increases.The balance area between silicon content,friction load,friction speed and friction coefficient can be effectively controlled,so that the friction and wear performance of Cu-Fe-Si alloy materials can reach the best state.(4)The wear resistance of Cu-Fe-Si alloy material mainly depends on the matrix structure.When the mass fraction of silicon exceeds 18%,too many brittle metal silicides are formed in the structure,resulting in loose structure and sharply reduced mechanical properties of the material.Macroscopically,the volume wear rate of the material increases significantly.The content of silicon in Cu-Fe-Si should be determined according to specific working conditions to achieve an organic balance between strength and wear resistance.(5)The wear mechanism is different under different working conditions.In the condition of 40N-600r/min,for example,silicon accounted for 5% of the sample,the wear mechanism is given priority to serious adhesive wear,silicon accounted for 10%of the sample,the wear mechanism mainly mild adhesive wear and abrasive wear is given priority to,the silicon content is 13% of the sample,in the process of friction surface abrasion mechanism is given priority to mild abrasive wear,15% of the sample containing silicon and the wear mechanism is given priority to surface fatigue wear and abrasive wear,containing silicon content is 18% of the sample,mainly serious abrasive wear.