Abstract: A method for manufacturing a polycrystalline silicon ingot includes unidirectionally solidifying a molten silicon upwardly from the bottom of a crucible, wherein the crucible is provided with silica deposited on the bottom of the crusible; and then dividing the degree of solidification in the crucible into a first zone from 0 mm to X in height (10 mm?X<30 mm), a second zone from X to Y in height (30 mm?Y<100 mm) and a third zone of Y or more in height, based on the bottom of the crucible, wherein a solidification rate V1 in the first zone is set in the range of 10 mm/h?V1?20 mm/h and a solidification rate V2 in the second zone is set in the range of 1 mm/h?V2?5 mm/h.

Abstract: A polycrystalline silicon ingot manufacturing apparatus, a polycrystalline silicon ingot manufacturing method, and a polycrystalline silicon ingot are provided. The apparatus comprises: a crucible having a rectangular shape in a cross-section; an upper heater provided above the crucible; and a lower heater provided below the crucible. A silicon melt stored in the crucible is solidified from a bottom surface of the crucible upward unidirectionally. The apparatus further comprises an auxiliary heater that heats at least a bottom-surface-side portion of a sidewall of the crucible. The production yield can be improved by using the apparatus and by reducing the oxygen concentration at the location where the oxygen concentration tends to be high locally at the bottom part of the ingot.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes: solidifying a silicon melt retained in a crucible unidirectionally upward from a bottom surface of the silicon melt, wherein a silicon nitride coating layer is formed on inner surfaces of side walls and an inner side surface of a bottom of the crucible, a solidification process in the crucible is divided into a first region from 0 mm to X (10 mm?X<30 mm) in hight, a second region from X to Y (30 mm?Y<100 mm), and a third region of the Y or higher, with the bottom of the crucible as a datum, a solidification rate V1 in the first region is in a range of 10 mm/h?V1?20 mm/h, and a solidification rate V2 in the second region is in a range of 1 mm/h?V2?5 mm/h.

Abstract: Provided are a layered crucible for casting a silicon ingot that can suppress dissolution of oxygen into the silicon ingot and a method of producing the same crucible. The layered crucible for casting a silicon ingot is used in the production of a silicon ingot by melting and casting a silicon raw material. The layered crucible comprising: a silica layer provided on the inner side of a mold; and a barium coating layer provided on the surface of the silica layer.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes unidirectionally solidifying a molten silicon upwardly from the bottom of a crucible, wherein the crucible is provided with silica deposited on the bottom of the crusible; and then dividing the degree of solidification in the crucible into a first zone from 0 mm to X in height (10 mm?X<30 mm), a second zone from X to Y in height (30 min?Y<100 mm) and a third zone of Y or more in height, based on the bottom of the crucible, wherein a solidification rate V1 in the first zone is set in the range of 10 mm/h?V1?20 mm/h and a solidification rate V2 in the second zone is set in the range of 1 mm/h?V2?5 mm/h.

Abstract: This metallic silicon is manufactured by refining molten crude metallic silicon by unidirectional solidification, and has a purity of 3N or more to 6N or less and an average crystal grain diameter of 1 mm or more. This method for manufacturing the metallic silicon includes: solidifying molten crude metallic silicon in a mold which contains fine silica particles in an inner peripheral layer thereof by unidirectional solidification at a rate of 1 mm/min or less; and then cooling to 200° C. or below at a rate of 2° C./min or less.

Abstract: This metallic silicon is manufactured by refining molten crude metallic silicon by unidirectional solidification, and has a purity of 3N or more to 6N or less and an average crystal grain diameter of 1 mm or more. This method for manufacturing the metallic silicon includes: solidifying molten crude metallic silicon in a mold which contains fine silica particles in an inner peripheral layer thereof by unidirectional solidification at a rate of 1 mm/min or less; and then cooling to 200° C. or below at a rate of 2° C./min or less.

Abstract: A mold for producing a silicon ingot having a layered structure comprising an inner silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a fine fused silica sand with a particle size of 100-300 &mgr;m is bonded with a silica binder, and an outer silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a coarse fused silica sand with a particle size of 500-1500 &mgr;m is bonded with a silica binder.

Abstract: A simple and inexpensive method and apparatus for producing crystalline silicon comprising the steps of melting silicon in a mold, then cooling the bottom of the mold is cooled to create a positive temperature gradient from the bottom of the mold upward, thereby causing the molten silicon to crystallize from the inner bottom of the mold upward so that the solid-liquid phase boundary, separating the crystallized silicon from the molten silicon, moves upward as the molten silicon crystallizes. As the silicon crystallizes, an inert gas is blown onto the surface of the molten silicon from a position above the surface of the molten silicon, thereby vibrating the surface of the molten silicon in such a manner that cavities are formed in the surface of the molten silicon.

Abstract: A simple and inexpensive method and apparatus for producing crystalline silicon comprising the steps of melting silicon in a mold, then cooling the bottom of the mold is cooled to create a positive temperature gradient from the bottom of the mold upward, thereby causing the molten silicon to crystallize from the inner bottom of the mold upward so that the solid-liquid phase boundary, separating the crystallized silicon from the molten silicon, moves upward as the molten silicon crystallizes. As the silicon crystallizes, an inert gas is blown onto the surface of the molten silicon from a position above the surface of the molten silicon, thereby vibrating the surface of the molten silicon in such a manner that cavities are formed in the surface of the molten silicon.

Abstract: A simple and inexpensive method and apparatus for producing crystalline silicon comprising the steps of melting silicon in a mold, then cooling the bottom of the mold is cooled to create a positive temperature gradient from the bottom of the mold upward, thereby causing the molten silicon to crystallize from the inner bottom of the mold upward so that the solid-liquid phase boundary, separating the crystallized silicon from the molten silicon, moves upward as the molten silicon crystallizes. As the silicon crystallizes, an inert gas is blown onto the surface of the molten silicon from a position above the surface of the molten silicon, thereby vibrating the surface of the molten silicon in such a manner that cavities are formed in the surface of the molten silicon.

Abstract: A method for producing a silicon ingot having a directional solidification structure comprising the steps of: placing a silicon raw material into a crucible of a melting device constructed by mounting a chill plate on an underfloor heater, mounting a crucible with a large cross-sectional area on the chill plate, providing an overhead heater over the crucible, and surrounding the circumference of the crucible with a heat insulator; heat-melting the silicon raw material by flowing an electric current through the underfloor heater and overhead heater; chilling the bottom of the crucible by halting the electric current through the underfloor heater after the silicon raw material has been completely melted to form a molten silicon; chilling the bottom of the crucible by flowing an inert gas through the chill plate; and intermittently or continuously lowering the temperature of the overhead heater by intermittently or continuously decreasing the electric current through the overhead heater, and an apparatus for pro

Abstract: A mold for producing a silicon ingot having a layered structure comprising an inner silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a fine fused silica sand with a particle size of 100-300 &mgr;m is bonded with a silica binder, and an outer silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a coarse fused silica sand with a particle size of 500-1500 &mgr;m is bonded with a silica binder.

Abstract: A mold for producing a silicon ingot having a layered structure comprising an inner silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a fine fused silica sand with a particle size of 100-300 &mgr;m is bonded with a silica binder, and an outer silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a coarse fused silica sand with a particle size of 500-1500 &mgr;m is bonded with a silica binder.

Abstract: A method for producing a silicon ingot having a directional solidification structure comprising the steps of: placing a silicon raw material into a crucible of a melting device constructed by mounting a chill plate on an underfloor heater, mounting a crucible with a large cross-sectional area on the chill plate, providing an overhead heater over the crucible, and surrounding the circumference of the crucible with a heat insulator; heat-melting the silicon raw material by flowing an electric current through the underfloor heater and overhead heater; chilling the bottom of the crucible by halting the electric current through the underfloor heater after the silicon raw material has been completely melted to form a molten silicon; chilling the bottom of the crucible by flowing an inert gas through the chill plate; and intermittently or continuously lowering the temperature of the overhead heater by intermittently or continuously decreasing the electric current through the overhead heater, and an apparatus for pro

Abstract: The present invention relates to a superior Fe--Cr alloy and a nozzle for diesel engines formed from this Fe--Cr alloy. The Fe--Cr alloy of the present invention comprises:______________________________________ C: 0.1.about.0.2% by weight Si: 0.1.about.2% by weight Mn: 0.1.about.2% by weight Cr: 16.about.20% by weight Mo: 1.1.about.2.4% by weight Nb: 0.3.about.2.1% by weight Ta: 0.1.about.2.2% by weight N: 0.02.about.0.15% by weight ______________________________________with a remaining portion therein consisting of Fe and unavoidable impurities. It is possible to substitute a portion of the Fe using 0.2.about.2.5% by weight of Co. Furthermore, in this case, it is also possible to substitute a portion of the Fe using at least one element selected from among 0.2.about.2.5% by weight of Ni and 0.2.about.2.5% by weight of W.

Abstract: A nickel-based alloy which is excellent not only in anti-corrosion properties but also in workability is disclosed. The alloy contains 15 to 35 weight % of chromium; 6 to 24 weight % of molybdenum; wherein the sum of chromium plus molybdenum is no greater than 43 weight %; 1.1 to 8 weight % of tantalum; and balance nickel and unavoidable impurities. The alloy may optionally include no greater than 0.1 weight % of nitrogen; no greater than 0.3 weight % of magnesium, no greater than 3 weight % of manganese, no greater than 0.3 weight % of silicon, no greater than 0.1 weight % of carbon, no greater than 6 weight % of iron, no greater than 0.1 weight % of zirconium, no greater than 0.01 weight % of calcium, no greater than 1 weight % of niobium, no greater than 4 weight % of tungsten, no greater than 4 weight % of copper, no greater than 0.8 weight % of titanium, no greater than 0.8 weight % of aluminum, no greater than 5 weight % of cobalt, no greater than 0.

Abstract: A coated valve face of an engine valve is formed of an Fe-based alloy having a composition consisting essentially of, by weight, 0.7 to 1.5% of C, 10 to 15% of Mn, 24 to 30% of Cr, 6.1 to 9.8% of Mo, 10 to 15% of Ni, 0.1 to 0.4% of N, 0.2 to 1.5% of Si, and optionally at least one of 0.1 to 5% of Nb, 0.1 to 5% of Ta and 0.15% of W as required (the total content of Nb, Ta and W being limited to 5% or less), and the balance substantially Fe and inevitable impurities, and having a two-phase structure formed of an austenitic phase and an eutectic carbide phase. In another embodiment, the composition contains between 0.05 to 1% Co. The Fe-based alloys are preferably applied to the valve face by plasma beam or laser beam coating of powdered such alloys onto the valve face.

Abstract: A Co-based alloy exhibits superior high-temperature strength and resistance properties. In one embodiment, the Co-based alloy contains, in weight percent, from about 0.1 to about 1.2 of C; from about 0.01 to about 2 of at least one of Si and Mn; from about 22 to about 37 of Cr; from about 5 to about 15 of Ni; from about 0.1 to about 3.5 of Re; with a balance being Co and incidental impurities. Co and C, Si, Mn, Cr, Ni, Re, B, Zr, W, Mo, Ta, and Nb impart high-temperature wear resistance to the alloy to withstand repeated temperature cycling in a glass spinnaret. In one embodiment of the present invention, Hf is added to improve molten glass corrosion resistance, while Y and other rare earth elements are added in alternate embodiments to improve high-temperature oxidation resistance. Percentages by weight are disclosed for enhanced high-temperature oxidation resistance, increased fluid wear resistance and enhanced molten glass corrosion resistance.

Abstract: A precipitation strengthening type nickel base single crystal alloy, which consists essentially of, on a weight percent basis,10-30% chromium,0.1-5% niobium,0.1-8% titanium,0.1-8% aluminum,optionally one or more components selected from the group consisting of 0.1-3% tantalum, 0.05-0.5% copper, 0.05-3% hafnium, 0.05-3% rhenium, 0.05-3% molybdenum, 0.05-3% tungsten, 0.05-0.5% boron, 0.05-0.5% zirconium, andthe remainder being nickel and incidental impurities, and exhibits a narrow solidification temperature range.