Abstract: A bearing mechanism including two substantially identical ball bearings, each having a longitudinal axis and an inner and an outer race with grooved surfaces facing each other in the races, said bearings being placed in a substantially parallel configuration once assembled in the resultant bearing mechanism, an inner tubular sleeve extending between and against the two substantially parallel ball bearings, said inner sleeve having a thickness and an outer diameter that substantially matches the dimensions of the inner and outer races of the ball bearings, and two bearing caps to be inserted through the two ball bearings, said bearing caps having a substantially tubular shape, each with a flange extending outwardly from one end of the tubular shaped bearing cap, the thickness of the flange matching the dimensions of the inner and/or outer race of the bearings such that, once assembled, the flanges contact the outside surfaces of the races of the substantially parallel ball bearings, thereby exerting a force on

Abstract: A bearing mechanism including two substantially identical ball bearings, each having a longitudinal axis and an inner and an outer race with grooved surfaces facing each other in the races, said bearings being placed in a substantially parallel configuration once assembled in the resultant bearing mechanism, an inner tubular sleeve extending between and against the two substantially parallel ball bearings, said inner sleeve having a thickness and an outer diameter that substantially matches the dimensions of the inner and outer races of the ball bearings, and two bearing caps to be inserted through the two ball bearings, said bearing caps having a substantially tubular shape, each with a flange extending outwardly from one end of the tubular shaped bearing cap, the thickness of the flange matching the dimensions of the inner and/or outer race of the bearings such that, once assembled, the flanges contact the outside surfaces of the races of the substantially parallel ball bearings, thereby exerting a force on

Abstract: A process for nitriding materials containing silicon to form a silicon nitride material predominantly in the alpha phase is disclosed which includes nitriding the silicon-containing material by (a) heating the silicon-containing material in an atmosphere containing at least hydrogen in the temperature range of about 0.degree. C. to about 800.degree. C. and (b) thereafter, nitriding the silicon-containing material by subjecting the silicon-containing material to a nitriding atmosphere containing at least nitrogen gas in the temperature range of from about 1000.degree. C. to about 1450.degree. C. to effect nitriding.

Abstract: A silicon-nitride beta-phase material including a non-densified structure of beta silicon nitride crystals having appreciable strength without any significant amount of liquid forming agents is made by comminuting a slurry including a mixture of silicon powder and water to form non-oxidized surfaces on the silicon powder and to allow chemical reaction between the silicon and the water, reducing the water content of the reacted slurry to a degree sufficient to form a resultant dry mass, nitriding the dry mass by exposure to a nitriding gas including at least nitrogen to form a mass of alpha-phase silicon nitride, and converting the resultant silicon nitride mass at a conversion temperature of from about 1450.degree. C. to about 2100.degree. C. to convert the silicon nitride from an alpha-phase material to a non-densified beta phase silicon nitride material.

Abstract: A method of converting non-densified alpha-phase silicon nitride to beta-phase silicon nitride which includes heating a walled container enclosing a non-densified alpha-phase silicon nitride mass to an elevated temperature for a sufficient length of time so that the non-densified alpha-phase silicon nitride mass converts to a beta-phase silicon nitride mass. The walled container is formed of a silicon nitride-containing material which is stable at temperatures of at least 1700.degree. C. and is compatible with silicon nitride. Additionally, the walled container has an opening therein to allow placement of the non-densified alpha-phase silicon nitride mass therein.

Abstract: A process for nitriding materials containing silicon to form a silicon nitride material predominantly in the alpha phase is disclosed which includes nitriding the silicon-containing material by (a) heating the silicon-containing material in an atmosphere containing at least hydrogen in the temperature range of about 0.degree. C. to about 1420.degree. C. and (b) thereafter, nitriding the silicon-containing material by heating the material in a nitriding atmosphere containing at least nitrogen gas in the temperature range of from about 1000.degree. C. to about 1450.degree. C.

Abstract: A process for preparing a nitridable silicon-containing material, which process includes comminuting a slurry of silicon powder, and water, the comminuting performed to cause substantial chemical reaction between the silicon and the water. Reducing the water content of the reacted slurry forms a processable mass. In another embodiment, desired additives such as at least one nitriding agent may be added to aid any nitridation or other processing which may be performed thereafter.

Abstract: A process for preparing an alpha-phase silicon nitride material and thereafter sintering to a densified beta-phase silicon nitride material is disclosed which includes comminuting a slurry including a mixture of silicon powder, water, and at least one densification aid to aid in later densifying of the silicon nitride material, the comminuting being performed to form fresh, non-oxidized surfaces on the silicon powder and to allow substantial chemical reaction between the silicon and the water, reducing the water content of the reacted slurry to a degree sufficient to form a resultant dry mass, nitriding the dry mass by exposure to a sufficient amount of a nitriding gas including at least nitrogen at a sufficient temperature for a sufficient length of time to form a mass of substantially alpha-phase silicon nitride, and sintering the resultant silicon nitride mass at a sintering temperature of from about 1450.degree. C. to about 2100.degree. C.

Abstract: A process for making silicon powder or articles of manufacture such as an internal combustion engine valve by comminuting a homogeneous water-base slurry of silicon powder and at least one nitriding agent and permitting the slurry to chemically react for a time sufficient to enable the chemical reaction to substantially reach completion, then reducing the water content sufficiently to form a powder or an article and thence nitriding the article or powder by continuously varying the temperature over the range of 1000.degree. C. to 1450.degree. C. using a nitriding gas comprising nitrogen, hydrogen and helium and maintaining a constant nitriding gas composition throughout the nitriding cycle.

Abstract: A process for preparing a nitridable silicon-containing material, which process includes (a) comminuting a slurry of silicon powder, water, at least one densification aid, including Al.sub.2 O.sub.3, and another densification aid, the comminuting performed to cause substantial chemical reaction between the silicon and the water; and (b) reducing the water content of the reacted slurry to form a dry mass. In another embodiment, at least one nitriding agent may be added to aid any nitridation which may be performed.

Abstract: A process for nitriding materials containing silicon to form a silicon nitride material predominantly in the alpha phase is disclosed which includes nitriding the silicon-containing material by subjecting it to a nitriding atmosphere containing at least nitrogen gas in combination with at least one other nitriding gas while keeping the composition of the nitriding atmosphere substantially constant by maintaining a substantially constant partial pressure of nitrogen gas during the nitriding, even though nitrogen is being consumed during the nitriding step to form the silicon nitride.

Abstract: A process for preparing an alpha-phase silicon nitride material and thereafter converting to non-densified beta-phase silicon nitride material includes comminuting a slurry including a mixture of silicon powder and water to form non-oxidized surfaces on the silicon powder and to allow chemical reaction between the silicon and water, reducing the water content of the reacted slurry to a degree sufficient to form a resultant dry mass, nitriding the dry mass by exposure to a nitriding gas including at least nitrogen to form a mass of alpha-phase silicon nitride, and converting the resultant silicon nitride mass at a conversion temperature of from about 1450.degree. C. to about 2100.degree. C. to convert the silicon nitride from an alpha-phase material to a non-densified beta phase silicon nitride material.

Abstract: An enclosable vessel for containing a silicon nitride article during sintering in a furnace to protect the silicon nitride article from thermal decomposition and contamination reactions with furnace materials comprises a closeable walled container formed of a reaction bonded silicon nitride material having an opening to allow interior placement of the silicon nitride article within the walled container. This box is used to replace silicon nitride powder which has heretofore been used to cover silicon nitride articles during sintering.

Abstract: A body of sintered silicon nitride contains new non-glassy phases which produce significant X-ray diffraction peaks at 2-theta diffraction angles corresponding to d-spacings of about 2.86 Angstroms and 3.59 Angstroms and process for making same, which process includes (a) comminuting a slurry of a silicon-containing powder, water, about 0.1 to 5 volume percent of Fe.sub.2 O.sub.3, about 0.1 to 5 volume percent Al.sub.2 O.sub.3, and about 0.5 to 10 volume percent CeO.sub.2, wherein all volume percents are based on the volume of the resultant silicon nitride, the composition of the slurry being such that about a 4 to 12 volume percent liquid phase is achieved during sintering; (b) reducing the water content of the reacted slurry to form a dry mass; (c) nitriding the dry mass by exposure to a nitriding gas at an elevated temperature to form silicon nitride; and (d) sintering the silicon nitride at about 1450.degree.-2100.degree. C.

Abstract: A process for preparing a nitridable silicon-containing material, which process includes (a) comminuting a slurry of silicon powder, water, at least one densification aid, including Al.sub.2 O.sub.3, and another densification aid, the comminuting performed to cause substantial chemical reaction between the silicon and the water; and (b) reducing the water content of the reacted slurry to form a dry mass. In another embodiment, at least one nitriding agent may be added to aid any nitridation which may be performed.

Abstract: A process for making silicon nitride articles of manufacture such as an internal combustion engine valve (2) by providing a homogeneous water-base slurry of silicon nitride powder and at least one nitriding agent and permitting the slurry to age for a time effective to enable a chemical reaction to occur and then reducing the water content sufficiently to form the article and thence forming and nitriding the article using a compound nitriding cycle.

Abstract: A process for making silicon nitride articles such as an internal combustion valve (8) by coating or causing silicon to grow on powdered silicon nitride particles through a vapor phase reaction and then forming and nitriding the articles in substantially less time than had the article been formed entirely from powdered silicon.