Abstract The invention is concerned with apparatus for manufacturing gas turbine engine components e.g. guide vanes and blades, in dense silicon nitride starting with silicon nitride in a powder form. Guide vanes are usually in the form of an aerofoil portion and two shroud portions and according to the invention, the aerofoil portion is made in a first mould by hot pressing a mixture of silicon nitride powder and a fluxing agent, such as magnesia. The formed aerofoil is placed in a second mould so that each end extends partly into a space which is to be filled with a further mixture of silicon nitride powder and a fluxing agent. The further mixtures are hot pressed both to form the shroud portions and to amalgamate the shroud portions with the aerofoil portion. Features, such as, flanges and webs can be formed in the shrouds during the moulding process or they can be machined into the shrouds after the vane is removed from the second mould.
An invertible moulding apparatus comprising: a housing, a split die contained within said housing, a split stationary retaining means located on a shoulder of the split die, at least one pressure applying plunger, and a locating plunger, the split stationary retaining means being capable of holding a first part of an article within the split die with at least one end of the first part of the article extending into a space within the split die between the split retaining means and the pressure applying plunger, the locating plunger being positioned within the split die to locate the first part of said article within the split die, the moulding apparatus being invertible and the locating plunger being removable and replaceable with a further pressure applying plunger.
Claim 2
Dependent Claim
126 words
An invertible moulding apparatus comprising: a housing, a split die contained within said housing, a split stationary retaining means located on a shoulder of the split die, at least one pressure applying plunger, and a locating plunger, the split stationary retaining means being capable of holding a first part of an article within the split die with at least one end of the first part of the article extending into a space within the split die between the split retaining means and the pressure applying plunger, the locating plunger being positioned within the split die to locate the first part of said article within the split die, the moulding apparatus being invertible and the locating plunger being removable and replaceable with a further pressure applying plunger.
Claim 3
Dependent Claim
38 words
An invertible moulding apparatus as defined in claim 1 wherein each pressure applying plunger is adapted to receive on its pressure applying face, a second part of an article which is to be formed within the moulding apparatus.