A study is performed on a newly developed Polycrystalline Diamond Cutter(PDC) with improved impact resistance.Impact resistance of PDC is dependent on diamond grain size,binder content and property of the substrate.A ...A study is performed on a newly developed Polycrystalline Diamond Cutter(PDC) with improved impact resistance.Impact resistance of PDC is dependent on diamond grain size,binder content and property of the substrate.A crack might initiate in the substrate by the impact transferred from the diamond layer if substrate is not tough enough to absorb it.This failure is caused by the residual stress at the interface resulting from the difference of thermal expansion coefficient between diamond and substrate. This kind of failure could be reduced to some extent by optimizing the grain size of WC and content of Co in the substrate.PDC with much improved impact resistance is produced by also optimizing the diamond size and the content of binder phase in the layer. Drop-test with different conditions of energy and speed are carried out on the newly developed PDC and wear resistance test is done and the result is compared with that of previous PDC. It is found that the newly developed PDC shows 40%better impact resistance than previous PDC.展开更多
In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting ...In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.展开更多
文摘A study is performed on a newly developed Polycrystalline Diamond Cutter(PDC) with improved impact resistance.Impact resistance of PDC is dependent on diamond grain size,binder content and property of the substrate.A crack might initiate in the substrate by the impact transferred from the diamond layer if substrate is not tough enough to absorb it.This failure is caused by the residual stress at the interface resulting from the difference of thermal expansion coefficient between diamond and substrate. This kind of failure could be reduced to some extent by optimizing the grain size of WC and content of Co in the substrate.PDC with much improved impact resistance is produced by also optimizing the diamond size and the content of binder phase in the layer. Drop-test with different conditions of energy and speed are carried out on the newly developed PDC and wear resistance test is done and the result is compared with that of previous PDC. It is found that the newly developed PDC shows 40%better impact resistance than previous PDC.
基金Suported by Advanced Technolgy center prject(No.10020604)
文摘In this study,newly developed low content PCBN was used to evaluate the cutting performance in high speed turning of hardened steel.Using new PCBN and commercially available PCBN tipped inserts under the same cutting condition,cutting performance with variable cutting speed,feed rate and depth of cuts on tools were measured by observation of flank and crater wear.Its microstructures were analyzed through SEM microscope,measurement of surface roughness on workpiece was also performed. According to cutting performance results,it is shown that new PCBN shows much longer tool life in high speed continuous turning than our conventional PCBN tools,with improved wear and chipping resistance.This result on the machinability of new PCBN for hardened steel will provide effective guidelines to manufacturing engineers,also provide useful economic machining solution for high speed continuous turning for hardened steel.
