Abstract: An artificial quartz crystal growth method that includes applying a pressure that causes at least two substantially rectangular-parallelepiped-shaped quartz crystal substrates to abut each other in an X-axis direction with crystallographic axis directions of the quartz crystal substrates aligned with each other, and causing the at least two quartz crystal substrates to grow an artificial quartz crystal in a state where the pressure is being applied.

Abstract: An artificial crystal growth method that includes applying a pressure that causes at least two substantially rectangular-parallelepiped-shaped crystal substrates to abut each other in an X-axis direction with crystallographic axis directions of the crystal substrates aligned with each other, and causing the at least two crystal substrates to grow an artificial crystal in a state where the pressure is being applied.

Abstract: A duplex eutectic silicon alloy including 30-70 weight % silicon, 10-45 weight % nitrogen, 1-40 weight % aluminum, and 1-40 weight % oxygen has a eutectic structure comprising a ??-sialon phase and an ??-sialon phase. The alloy is produced by controlling cooling at a rate of 50° C. or less per minute in combustion synthesis. A ductile sintered product capable of replacing steel in various applications can be produced by placing a compact composed of a powder of the alloy in a sintering furnace which can supply a heat quantity at least ten times the heat capacity of the compact; and sintering the compact at a pressure at least as great as atmospheric pressure, within a nitrogen atmosphere in which the silicon gas mole fraction is 10% or more, and at a temperature within the range from 1400° C. to 1700° C.

Abstract: A duplex eutectic silicon alloy including 30-70 weight % silicon, 10-45 weight % nitrogen, 1-40 weight % aluminum, and 1-40 weight % oxygen has a eutectic structure comprising a ??-sialon phase and an ??-sialon phase. The alloy is produced by controlling cooling at a rate of 50° C. or less per minute in combustion synthesis. A ductile sintered product capable of replacing steel in various applications can be produced by placing a compact composed of a powder of the alloy in a sintering furnace which can supply a heat quantity at least ten times the heat capacity of the compact; and sintering the compact at a pressure at least as great as atmospheric pressure, within a nitrogen atmosphere in which the silicon gas mole fraction is 10% or more, and at a temperature within the range from 1400° C. to 1700° C.

Abstract: Dehydration and drying of a silicon alloy argil which uses water as a principal binder are carried out by a freeze-drying process, a microwave irradiation process, or a combination thereof. In the freeze-drying process, the shaped compact is put into a cooling medium within 5 minutes after completion of shape forming, retained therein for at least 5 minutes to quick-freeze water within the compact while the water is still in a finely-dispersed condition. The compact is exposed to a pressure below the triple point pressure of water. In the microwave irradiation process, the shaped compact is put into a container exposed to continuous microwave irradiation at 2.450 GHz for at least 5 minutes while under a reduced pressure below atmospheric pressure.