TY - JOUR
T1 - Graphite–boron composite heater in a Kawai-type apparatus
T2 - the inhibitory effect of boron oxide and countermeasures
AU - Xie, Longjian
AU - Yoneda, Akira
AU - Yoshino, Takashi
AU - Fei, Hongzhan
AU - Ito, Eiji
PY - 2016/4/2
Y1 - 2016/4/2
N2 - ABSTRACT: We have investigated the performance of a graphite–boron composite (GBC) with 3 wt % boron as a precursor for a boron-doped diamond heater in a Kawai-type apparatus at 15 GPa. We first tested a machinable cylinder of GBC sintered at 1000°C in Ar/H2 gas (99:1 molar ratio). Boron oxide (B2O3) formed during sintering frequently hindered the GBC heater from stable operation at temperatures higher than 1400°C by producing melt throughout the heater together with oxide and/or silicates. We then rinsed the GBC heater in hydrochloric acid to remove B2O3. After rinsing, we succeeded in stably generating temperatures higher than 2000°C. We also improved a molding process of different-sized GBC tubes for convenient use and tested the molded GBC heater. It was free from the B2O3 problem. The electromotive force of the W/Re thermocouple was successfully monitored up to 2400°C.
AB - ABSTRACT: We have investigated the performance of a graphite–boron composite (GBC) with 3 wt % boron as a precursor for a boron-doped diamond heater in a Kawai-type apparatus at 15 GPa. We first tested a machinable cylinder of GBC sintered at 1000°C in Ar/H2 gas (99:1 molar ratio). Boron oxide (B2O3) formed during sintering frequently hindered the GBC heater from stable operation at temperatures higher than 1400°C by producing melt throughout the heater together with oxide and/or silicates. We then rinsed the GBC heater in hydrochloric acid to remove B2O3. After rinsing, we succeeded in stably generating temperatures higher than 2000°C. We also improved a molding process of different-sized GBC tubes for convenient use and tested the molded GBC heater. It was free from the B2O3 problem. The electromotive force of the W/Re thermocouple was successfully monitored up to 2400°C.
KW - Kawai-type apparatus
KW - boron-doped diamond
KW - graphite–boron composite
UR - http://www.scopus.com/inward/record.url?scp=84961391617&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84961391617&partnerID=8YFLogxK
U2 - 10.1080/08957959.2016.1164151
DO - 10.1080/08957959.2016.1164151
M3 - Article
AN - SCOPUS:84961391617
VL - 36
SP - 105
EP - 120
JO - High Pressure Research
JF - High Pressure Research
SN - 0895-7959
IS - 2
ER -