Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A method of manufacturing an article of ceramic material, comprising the steps of (a) forming a plurality of shaped article parts from a composition containing a powder of ceramic material, at least one of said shaped article parts formed from a composition containing a powder of ceramic material mixed with a plasticizer, (b) driving off the plasticizer contained in said at least one shaped article part, (c) assembling said plurality of shaped article parts together into a configuration conforming to that of the article to be manufactured, at least one gap being left between two of the assembled shaped article parts, (d) applying sufficient jointing material comprising a powder mixed with a plasticizer over the gaps between the assembled shaped article parts to bridge said gaps, (e) driving off the plasticizer from said jointing material, (f) surrounding the assembled article parts with a gas-impermeable layer, and (g) isostatically pressing the assembled article parts at elevated temperature.
Claim 2
Independent Claim
156 words
A method of manufacturing an article of ceramic material, comprising the steps of (a) forming a plurality of shaped article parts from a composition containing a powder of ceramic material, at least one of said shaped article parts formed from a composition containing a powder of ceramic material mixed with a plasticizer, (b) driving off the plasticizer contained in said at least one shaped article part, (c) assembling said plurality of shaped article parts together into a configuration conforming to that of the article to be manufactured, at least one gap being left between two of the assembled shaped article parts, (d) applying sufficient jointing material comprising a powder mixed with a plasticizer over the gaps between the assembled shaped article parts to bridge said gaps, (e) driving off the plasticizer from said jointing material, (f) surrounding the assembled article parts with a gas-impermeable layer, and (g) isostatically pressing the assembled article parts at elevated temperature.
Claim 3
Dependent Claim
15 words
The method as claimed in claim 1, wherein said gas-impermeable layer is made of glass.
Claim 4
Dependent Claim
51 words
The method as claimed in claim 1, wherein said gas-impermeable layer is made of a layer of a glass material which forms a gas-impermeable layer when heated, and wherein said method includes between steps (f) and (g) the step of heating said layer of glass material to form said gas-impermeable layer.
Claim 5
Dependent Claim
28 words
The method as claimed in claim 1, wherein a first of said shaped article parts has a greater cross-sectional area than a second of said shaped article parts.
Claim 6
Dependent Claim
60 words
The method as claimed in claim 4, wherein in step (a) said first and second shaped article parts are each formed by pressing a composition containing a mixture of powder of ceramic material and a plasticizer, the plasticizer employed in forming said first article part having a lower molecular weight than the plasticizer employed in forming said second article part.
Claim 7
Dependent Claim
17 words
The method as claimed in claim 1, wherein said powder of ceramic material is silicon nitride powder.
Claim 8
Dependent Claim
31 words
The method as claimed in claim 6, wherein said plasticizer is selected from the group consisting of methyl cellulose, cellulose nitrate, an acrylic binder, a wax and a mixture of waxes.
Claim 9
Dependent Claim
39 words
The method as claimed in claim 1, wherein said shaped article parts consist of a hub part which includes a shaft and a ring part which includes projecting blades, the manufactured article of ceramic material being a turbine wheel.
Claim 10
Dependent Claim
44 words
The method as claimed in claim 8, wherein said ring part is made of a material having a high creep strength at a high temperature and said hub part is made of a material having a high strength at a low or medium-high temperature.