Abstract:
A process for manufacturing a ceramic foundry core having at least one thin region with a thickness “e”, in particular in of a turbomachine blade trailing edge, including the forming in a mold of a mixture including a ceramic particle filler and an organic binder, the extraction of the core from the mold, the binder removal and consolidation heat treatment of the core. The process is one in which a core is formed in the mold, the region of this core being thickened relative to the thickness “e” by an overthickness E and in which the overthickness is machined after the core has been extracted from the mold and before or after the heat treatment operation. In particular, the machining is carried out mechanically by milling, either with removal of chips on the cores before firing, or by abrasion on the fired cores.
Abstract:
The present invention relates to a tool for manufacturing a casting core, for a turbomachine blade with a leading edge and a trailing edge, the core (10) comprising a thick part on the leading edge side and a thin part (10A1) on the trailing edge side, comprising first and second dies (530, 540) of the core that can move in a direction (F′1 and F′2 respectively) one with respect to the other between a molding position and a demolding position, where appropriate with sub-components that can move relative to the dies, wherein the parts of the dies corresponding to said thin part of the core do not include a movable sub-component, mechanical ejectors (570) being provided on one or other of the dies, in such a way that the thin part (10A1) of the core is demolded along the main direction of opening.
Abstract:
This hydraulic machine member has at least one flow of water passing through it, and comprises at least one wetted surface extending between two edges of the member, at least one of the edges of the member and part of the adjacent wetted surface being reinforced and formed by at least one removable solid element made from material having a high resistance to abrasion.
Abstract:
The present invention relates to a method for deburring a ceramic foundry core (10) obtained by injecting a ceramic paste, said paste including a binder having a predetermined glass transition temperature, into a mold and having at least one surface portion with a surplus of material forming a burr (B) to be eliminated. The method is characterized in that it includes the following stages: a) disposing and attaching the molded, unfired foundry core (10) onto a mounting (300); b) placing a milling tool (100), having an elongated shape with a helically cut edge, onto a tool holder; c) causing the tool to rotate around its axis and touching the milling tool to said surface portion to be deburred; and d) freezing (400) the surface portion to be deburred such that the foundry core is maintained at a temperature lower than said glass transition temperature during the deburring operation.
Abstract:
The device (100) serves to separate solid particles from the water of a flow (E) feeding a hydraulic machine of the turbine, pump, or turbine-pump type. The device has flow inlet and outlet zones (104, 105) for the flow that are spaced apart along an advance axis (X100) of flow advance-through the device (100). The device (100) comprises a plurality of ducts (110) placed in parallel, each having a mouth and a downstream end between the inlet zone (104) and the outlet zone (105). In section perpendicular to the advance axis (X100), each duct presents a section in the form of a spiral with a radius of curvature that increases from the mouth towards the downstream end or from the downstream end towards the mouth, with each duct (110) presenting a thickness measured in a generally radial direction relative to the advance axis that is less than 10% of the width (l110) of said duct, measured parallel to said axis (X100).
Abstract:
The invention relates to a method of manufacturing a cast ceramic core comprising at least one recess, particularly for partitions, for a turbomachine blade in particular, comprising the shaping in a mould of a mixture containing a ceramic particles filler and an organic binder, extraction of the core from the mould, removal of the binder and a heat treatment to consolidate the core. The method is characterized in that a core rough casting without the said recess is formed in the said mould and in that the said recess is machined once the rough casting has been extracted from the mould and before the heat treatment operation. In particular, the machining operation is performed mechanically by milling with the removal of chips. The invention also relates to a tool suited to implementing the method.
Abstract:
A composition for the preparation of articles of calcium oxide, comprising calcined calcium oxide and an organic phase consisting of at least one polyol in an anhydrous medium. The composition may be used to form linings for molds and crucibles intended to come into contact with molten metals of groups IV and V of the periodic table.
Abstract:
A method for protecting a component of a hydraulic machine against erosion comprises steps involving preparing, in the flat state, several sheets of polymerised synthetic material, in applying a coat of adhesive to one side of each sheet 300 and in laying the sheets on the surface of the component that is to be covered with the layer of coating.
Abstract:
A tool for manufacturing a casting core, for a turbomachine blade with a leading edge and a trailing edge, the core includes a thick part on the leading edge side and a thin part on the trailing edge side is disclosed. The tool includes first and second dies of the core that are moveable in a direction with respect to each other between a molding position and a demolding position, sub-components that are moveable relative to the dies, and mechanical ejectors that are provided on the first and second dies. The parts of the dies corresponding to the thin part of the core do not include a movable sub-component. The thin part of the core is demolded along the main direction of opening of the first and second dies.
Abstract:
This hydraulic machine member has at least one flow of water passing through it, and comprises at least one wetted surface extending between two edges of the member, at least one of the edges of the member and part of the adjacent wetted surface being reinforced and formed by at least one removable solid element made from material having a high resistance to abrasion.