Research On The Surface Modification Of Titanium Alloy Metal Belt And The Wear Life Under High Speed Conditions

Under the overall trend of energy conservation and environmental protection and consumption upgrading,new energy vehicles have developed rapidly,of which pure electric vehicles occupy a primary position in the new energy vehicle market.Because CVT has the advantages of low fuel consumption,simple operation,and efficient matching with the motor to improve the vehicle mileage,it is considered to be the ideal transmission device for electric vehicles,and will even gradually replace other transmissions as the mainstream trend of future development.However,under the condition of high speed,the transmission efficiency and reliability of CVT metal belt will be reduced,and in view of this problem,the measures of selecting TC4 titanium alloy material instead of the original metal belt material are proposed.Due to the low hardness and poor wear resistance of titanium alloy,this paper proposes to improve the preparation of wear-resistant coatings on its surface to enhance the wear resistance of titanium alloy metal sheets,and the microstructure,mechanical properties and wear life of titanium alloy metal sheets before and after modification have been studied.The specific research contents are as follows:(1)The transmission principle and core components of CVT are expounded,and the relational expressions among parameters such as wrap angle,belt length and center distance are deduced according to the unique geometric relationship of CVT.The mechanical model of the metal sheet and the belt ring under the condition of transmission ratio i>1 is established,and the calculation formula of its key force is deduced,which provides support for the follow-up research.(2)The relationship between the pushing force between the metal sheets,the tension of the belt ring and the centrifugal force with the rotation speed was compared and studied after the metal belt was made of titanium alloy material or the raw material,and it was discussed whether the use of titanium alloy material could enhance the transmission efficiency of the metal belt under the condition of high rotation speed.(3)In order to improve the hardness value of titanium alloy sheet and improve its wear resistance,this paper uses the modification method of laser cladding to prepare two kinds of wear-resistant Ni60+50%WC and d22 base+(Ni60+50%WC)on its surface.In addition,the relevant research and analysis are carried out on the structure,hardness,wear resistance and bonding strength of the wear-resistant coating,and Ni60+50%WC,d22 base +(Ni60+50%WC),GCr15 bearing steel and TC4 titanium The hardness and wear experiments of the four alloy materials were compared and analyzed to discuss whether the titanium alloy metal sheets before and after modification could meet the requirements of metal sheets in terms of hardness and wear resistance.(4)The wear type and surface morphology of the metal sheet were analyzed,and the wear life of the metal sheet under high-speed conditions was studied.The wear life model of the metal sheet is deduced by the Archard model,and the wear life of the vehicle is characterized by the total mileage of the vehicle.