Study Of Developing The Properties Of Gear Transmission Pairs Based On Low Temperature Surface Modification Technologies

Gear transmission is one of the most important power and transmission forms for machinery and mechanical equipment. With the development of modern industry, gears are hoped to be used under bad conditions or to be worked in friendly environment, the requirements of the performance of gears are emphasized. As a result, it is of great importance to study the new technology and materials'application on gears, to improve the quality and performance of gears, reduce the cost of manufacture and use, decrease pollution, energy and resource consumption. It has been emphasized on gear research currently. This project is one of the major parts of the project "study based on PVD technologies on raising the surface properties of transmission parts"which is a 211 project of ChongQing university,and a part of the open fund project of State Key Laboratory of Mechanical Transmission of Chongqing University,and also the main content of cooperation perject between Chongqing University and YanBian University. In this study, TiN and C:N coatings are made on 20CrMo gears by Multi-arc Ion Plating technology and DFAD(Direct Current Filtered Arc Deposition) technology. Then put onto the test rig, working under the condition of 1 800 rpm,12 N.m for 50 hours, and the observations by body-microscope shows that reducing wear and wear-resistance performance greatly enhanced when C:N film is used , TiN coatings can not however ,because the hardness of gears is evidently decreased when coating was processing. So, in this paper, DFAD(Direct Current Filtered Arc Deposition) technology are used on gears to improve the performance of reducing wear and wear resistance . A detailed study is carried out on the deposition of ceramic coating and super-rigidity coating on gear surface with high adhesion. And providing academic and experimental data for high intensity, high toughness, wear resistance, environment-protect gears with long life. Major work in this paper is as follows: ①Heat treatment and carbonized before processing . The hardness of the surface of 20CrMo gears is hoped to be improved, as to provide a good support to the harder materials: TiN and C:N coatings deposited by Multi-arc Ion Plating and DFAD(Direct Current Filtered Arc Deposition). ②TiN and C:N coatings, deposited by Multi-arc Ion Plating technology and DFAD(Direct Current Filtered Arc Deposition) , are coated on gears and specimen . ③Metallographs of the surface of the gears made of 20CrMo and coated with TiN and C:N specimen are taken and Microstructures of them are analysised. ④Testing and analyzing the hardness of the gears made of 20CrMo and those coated with TiN and C:N . ⑤testing and analyzing the thickness and adhesive power of the films. ⑥Do the Ball on Disc experiment on specimen. ⑦Building test rig and putting the gears onto it , gears worked under the conditions of 1 800 rpm,12 N.m for 50 hours. Taking surface morphology photos and analyse the weight and length of common normal of the gears before and after experiment The results indicate that the performance of reducing wear and wear-resistance greatly enhanced when C:N film is used.