The performances of ceramic inserts in cutting nickel-based alloy were investigated. A new cutting test-bed was devised and used to deburr. The burr height on the working surface with notch wear in deburring cutting w...The performances of ceramic inserts in cutting nickel-based alloy were investigated. A new cutting test-bed was devised and used to deburr. The burr height on the working surface with notch wear in deburring cutting was compared with that in normal cutting. The impact force, impact pressure, and impact frequency of the saw-tooth-shaped chip edge on rake face and cutting edge at different speeds were calculated, and the influence of chip edge on notch wear formation was analyzed. A new tool design for reducing notch wear was presented, which is flexible and can deburr effectively.展开更多
In this paper the laser activities of a diode-pumped Yb：LuAG ceramic which was prepared by the solid-state reactive sintering method were reported. The maximum output power was 1.86 W in the continuous wave（CW） las...In this paper the laser activities of a diode-pumped Yb：LuAG ceramic which was prepared by the solid-state reactive sintering method were reported. The maximum output power was 1.86 W in the continuous wave（CW） laser operation,corresponding to a slope efficiency of 53.6%. The CW laser could be tuned from 1030 to 1096 nm by inserting a prism in the cavity. With the assist of a semiconductor saturable absorber mirror（SESAM）, passive mode-locking was realized,delivering sub-picosecond pulses with 933 fs duration and an average power of 532 m W at a repetition rate of 90.35 MHz.展开更多
Duplexα/β-SiAlON ceramic cutting inserts(30α:70β)were synthesized by microwave sintering.The effects of solid solution parameters(m,n,z),synthesis temperature,and amount of excess Y_(2)O_(3) synthesis additive on ...Duplexα/β-SiAlON ceramic cutting inserts(30α:70β)were synthesized by microwave sintering.The effects of solid solution parameters(m,n,z),synthesis temperature,and amount of excess Y_(2)O_(3) synthesis additive on phase assemblage,microstructure,mechanical properties,and cutting performance were systematically investigated.It was found that increasing m value could improve the formation ofαphase while high z value over 1.0 resulted in the dissolution ofαphase intoβphase and intergranular phase.Increasing the amount of excess Y_(2)O_(3) could promote densification and elongatedβgrain growth;however,the excess Y_(2)O_(3) amount above 4 wt%resulted in substantial crystallization of M'SS phase,thus declining the mechanical properties and wear resistance.The microwave-synthesizedα/β-SiAlON cutting insert with modified parameters(m=1.7,n=1.0,z=0.7,and 3 wt%excess Y_(2)O_(3))was obtained with optimal comprehensive properties,whose tool life was found to increase by approximately 75%in high-speed milling of Inconel 718 superalloy compared to the commercialα/β-SiAlON cutting insert.展开更多
文摘The performances of ceramic inserts in cutting nickel-based alloy were investigated. A new cutting test-bed was devised and used to deburr. The burr height on the working surface with notch wear in deburring cutting was compared with that in normal cutting. The impact force, impact pressure, and impact frequency of the saw-tooth-shaped chip edge on rake face and cutting edge at different speeds were calculated, and the influence of chip edge on notch wear formation was analyzed. A new tool design for reducing notch wear was presented, which is flexible and can deburr effectively.
基金Project supported by the National Major Scientific Instruments Development Project of China(Grant No.2012YQ120047)the National Key R&D Program of China(Grant No.2016YFB0402105)+1 种基金the National Natural Science Foundation of China(Grant Nos.61205130 and 61575212)the Key Research Project of the Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-JSC022)
文摘In this paper the laser activities of a diode-pumped Yb：LuAG ceramic which was prepared by the solid-state reactive sintering method were reported. The maximum output power was 1.86 W in the continuous wave（CW） laser operation,corresponding to a slope efficiency of 53.6%. The CW laser could be tuned from 1030 to 1096 nm by inserting a prism in the cavity. With the assist of a semiconductor saturable absorber mirror（SESAM）, passive mode-locking was realized,delivering sub-picosecond pulses with 933 fs duration and an average power of 532 m W at a repetition rate of 90.35 MHz.
基金The work is supported by the National Natural Science Foundation of China(Nos.51875291 and 52075266)the Excellent Youth Fund of Jiangsu Province(No.BK20190070)the Fundamental Research Funds for the Central Universities(No.30920032206).
文摘Duplexα/β-SiAlON ceramic cutting inserts(30α:70β)were synthesized by microwave sintering.The effects of solid solution parameters(m,n,z),synthesis temperature,and amount of excess Y_(2)O_(3) synthesis additive on phase assemblage,microstructure,mechanical properties,and cutting performance were systematically investigated.It was found that increasing m value could improve the formation ofαphase while high z value over 1.0 resulted in the dissolution ofαphase intoβphase and intergranular phase.Increasing the amount of excess Y_(2)O_(3) could promote densification and elongatedβgrain growth;however,the excess Y_(2)O_(3) amount above 4 wt%resulted in substantial crystallization of M'SS phase,thus declining the mechanical properties and wear resistance.The microwave-synthesizedα/β-SiAlON cutting insert with modified parameters(m=1.7,n=1.0,z=0.7,and 3 wt%excess Y_(2)O_(3))was obtained with optimal comprehensive properties,whose tool life was found to increase by approximately 75%in high-speed milling of Inconel 718 superalloy compared to the commercialα/β-SiAlON cutting insert.
