Device Design Improvements And Technological Study On High Speed Steel Cutter Cryogenic Treatment

With the development of modern manufacturing technology,the machining processing capacity and processing efficiency has a higher request in aerospace,automotive,tooling and other industries.Life of cutting tool was severely reduced during profiling hard-to-cut material that has great impact on tool's wearing.The key to improve the life of cutting tool is the way to improve the wear resistance of the cutting tool material,and it's also the main research direction to improve overall performance of cutting tools.Cryogenic treatment as an extension of the conventional heat treatment can improve strength,toughness and wear resistance of materials.The deep cryogenic treatment equipment and processes including coolant,holding time and the sequence of processes have a great influence on the treatment effect.Firstly,the paper proposed a composite heat exchange system and device designed the deep cryogenic treatment equipment based on the analysis of radiant heat exchange system and convection heat exchange system combining with the advantages of both.The equipment can control the temperature more accurately,the internal temperature of that is well-distributed,and structure is simple,etc.Secondly,this paper study of cryogenic process parameters and proposes a method based on the Martensitic transformation theory to solve the cryogenic time and temperature.The M2 end mills were used as the experimental object,and the test was conducted using the developed equipment to verify the method.Hardness tests and cutting experiments were used to evaluate the effect of cryogenic treatment.Experimental results show that the longer the cryogenic time,the lower the temperature,the better wear resistance.However,with the increase of the time and temperature,the cryogenic effect was showing rapid increase first,after slow growth.it is consistent with the speculated results;under the experimental condition,the best cryogenic process is-194 ?×2 h×5 ?/min×2 times,cutting tool wear resistance increased by 47.5%,the combinations of optimal process levels is calculated the optimal solution of cryogenic temperature and time.Finally studied the cryogenic treatment on the influence of the cutting tool wear resistance,the research results showed that the cryogenic effect after twice cryogenic were better than that of a cryogenic,hardness and wear resistance increase most obviously after several times of cryogenic treatment at-194?;A comparison of the cutter's wear morphology before and after cryogenic processing revealed that the cryogenic cutter has lighter burn,lower adhesive wear,better heat dissipation,lower oxidation wear and better wear resistance.