Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide...Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide.Boron carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering additive.The present study investigated the effect of Ti_(3)SiC_(2) addition to boron carbide by reactive spark plasma sintering in the range of 1700-1900℃.Ti_(3)SiC_(2) phase decomposed at high temperatures and reacted with B4C to form secondary phases of TiB2 and SiC.The results demonstrated that the increase of Ti_(3)SiC_(2) addition(up to 15 vol%)effectively promoted the densification of B4C and yielded higher hardness.However,as the amount of Ti_(3)SiC_(2) increased further,the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.展开更多
5月1日,学会理事白雪冬团队与国内多家单位合作在Nature期刊发表了一项题为“Bevel-edge epitaxy of ferroelectric rhombohedral boron nitride single crystal”的最新成果。报道了一种使用斜边外延来制备厘米尺寸单晶菱方氮化硼层的...5月1日,学会理事白雪冬团队与国内多家单位合作在Nature期刊发表了一项题为“Bevel-edge epitaxy of ferroelectric rhombohedral boron nitride single crystal”的最新成果。报道了一种使用斜边外延来制备厘米尺寸单晶菱方氮化硼层的简单方法,在相邻镍表面上具有精确的层间ABC堆叠。该研究成功实现了在单晶镍基板上的精确制造,在斜面(110)处有台阶边缘的阶梯形(100),同时引导BN层中一致的硼氮键取向,并通过每个斜面附近的成核来引导BN层的菱面体堆叠。展开更多
Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and s...Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and scanning electron microscope.The phase diagram of BP was explored in both B-rich and P-rich environments,revealing crucial insight into its behavior at 5.0 GPa.Additionally,we measured the melting curve of BP from 8.0 GPa to 15.0 GPa.Our findings indicate that the stability of BP under high pressure is improved within B-rich and P-rich environments.Furthermore,we report a remarkable observation of melting curve frustration at 10.0 GPa.This study will enhance our understanding of stability of BP under high pressure,shedding light on its potential application in semiconductor,thermal,and light-transmitting devices.展开更多
基金YOK(MEVLANA 2018-9999-Proj-ect-Based International Exchange Programme)for financial support in inter-national collaboration.
文摘Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its applications.One approach to overcome this limitation is the addition of secondary phases into boron carbide.Boron carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering additive.The present study investigated the effect of Ti_(3)SiC_(2) addition to boron carbide by reactive spark plasma sintering in the range of 1700-1900℃.Ti_(3)SiC_(2) phase decomposed at high temperatures and reacted with B4C to form secondary phases of TiB2 and SiC.The results demonstrated that the increase of Ti_(3)SiC_(2) addition(up to 15 vol%)effectively promoted the densification of B4C and yielded higher hardness.However,as the amount of Ti_(3)SiC_(2) increased further,the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.
文摘5月1日,学会理事白雪冬团队与国内多家单位合作在Nature期刊发表了一项题为“Bevel-edge epitaxy of ferroelectric rhombohedral boron nitride single crystal”的最新成果。报道了一种使用斜边外延来制备厘米尺寸单晶菱方氮化硼层的简单方法,在相邻镍表面上具有精确的层间ABC堆叠。该研究成功实现了在单晶镍基板上的精确制造,在斜面(110)处有台阶边缘的阶梯形(100),同时引导BN层中一致的硼氮键取向,并通过每个斜面附近的成核来引导BN层的菱面体堆叠。
基金Project supported by the National Natural Science Foundation of China (Grant No.12074273)the Sichuan Science and Technology Program (Grant No.2022NSFSC1810)。
文摘Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and scanning electron microscope.The phase diagram of BP was explored in both B-rich and P-rich environments,revealing crucial insight into its behavior at 5.0 GPa.Additionally,we measured the melting curve of BP from 8.0 GPa to 15.0 GPa.Our findings indicate that the stability of BP under high pressure is improved within B-rich and P-rich environments.Furthermore,we report a remarkable observation of melting curve frustration at 10.0 GPa.This study will enhance our understanding of stability of BP under high pressure,shedding light on its potential application in semiconductor,thermal,and light-transmitting devices.
