Preparation And Noise Reduction Of CrN Coating On Cemented Carbide Saw Blade

As a cutting tool,carbide circular saw blades are widely used for cutting and grooving metal materials,and are also the most commonly used cutting tools for wood processing.During cutting,friction and wear between the tool and the workpiece material are the main factors that cause tool failure and shortened life.The formation of a special hard coating on the surface of the tool has become the main way to improve the machining accuracy,extend the service life of the tool and reduce the production cost.In addition,when the circular saw blade cuts the workpiece,the contact friction between the high-speed rotating circular saw blade and the workpiece will produce violent noise,which will cause great harm to the workers' physical and mental health and workshop environment.By optimizing the structure of the circular saw blade,the noise can be effectively reduced,the physical and mental health of the workers can be protected,and the production quality can be improved.This article uses the common tool material YG6 cemented carbide as the matrix material,magnetron sputtering technology is used on the test piece to prepare CrN coating,The influence law of nitrogen flow ratio,substrate temperature and sputtering power on the morphology,element composition,mechanical properties and tribological properties of CrN coatings were discussed;XRD,SEM,hardness tester,scratch tester,friction and wear tester were used to characterize the morphology,structure,microhardness,membrane adhesion and friction coefficient of the coating,so as to optimize the process parameters of coating design and preparation.Studies have shown that CrN coatings can be successfully prepared at different nitrogen flow ratios,sputtering powers and substrate temperatures.The main phases of the coatings are:Cr,Cr2 N and CrN.With the increase of nitrogen flow ratio,the growth mode of the coating changed from columnar growth to triangular growth mechanism,the density increased,and the microhardness increased first and then decreased;when the nitrogen flow ratio is increased to 40%,the microhardness is the highest,the density is high,and the shape is triangular.With the increase of sputtering power,the growth method of coating changed from triangular pyramid growth to circular growth mechanism,At 55 W,75W,and 95 W,the coating particles are in a triangular shape,and at 105 W,the coating grows in a circular shape,and the microhardness increases first and then decreases;When the sputtering power is 75 W,the microhardness is the largest at this time.As the sputtering power continues to increase,the thickness of the coating also increases,but the hardness and bonding force of the coating gradually decrease.With the increase of the substrate temperature,the growth of the coating mainly showed triangular pyramid growth,and the density did not change much.The microhardness first decreased and then increased.When the temperature reached 300?,the maximum reached 1843.4HV.Based on the composition of the CrN coating,Si and Ti elements with different contents are added to discuss the influence of Si and Ti element contents on the coating morphology,mechanical properties and tribological properties of the prepared coating.The test shows that with the increase of Si sputtering power,the hardness of CrSiN coating increases first and then decreases.When the Si atomic fraction content is 14.1%,the maximum hardness reaches 2397.6HV.With the addition of Si element,the wear resistance is improved.When the Si atomic fraction of the coating is 14.1%,the wear rate is the smallest.With the increase of Ti sputtering power,the hardness of the coating increases first and then decreases.When the Ti atomic fraction content is 29.6%,the maximum hardness is3840.8HV,The addition of Ti element can make the grain size of CrN coating smaller,and the grain size is within the range of 20-90 nm.The addition of Ti element has the effect of solid solution strengthening.With the further increase of Ti sputtering power,Ti atoms replace Cr atoms,which makes the bonding force of the coating continuously decrease.Using Workbench to analyze the dynamic characteristics of the circular saw blade,the natural frequency and various modes of vibration are obtained.The dynamic characteristics of circular saw blades are closely related to the vibration and noise of circular saw blades.The structure of the circular saw blade(such as the thickness of the circular saw blade,the number and position of noise reduction holes,the hole distance,etc.)is the main factor affecting the dynamic characteristics of the circular saw blade.According to the modal analysis of circular saw blades,circular saw blades have good structural noise reduction performance when the diameter is 200 mm,the thickness is 2mm,the number of noise reduction holes is 4,the aperture is 10 mm,and the hole distance is 60 mm.