Superplastic forming machine and a method of superplastic forming

A method of superplastic forming comprising the steps of:

• a) providing a superplastic forming machine comprising:
• a frame;
• first and second parallel spaced apart platens, each arranged in a plane normal to a displacement axis;
• a first displacement mechanism connected to the first platen and configured to displace the first platen along the displacement axis;
• a locking mechanism which can be configured in a locked configuration in which the locking mechanism prevents displacement of the first platen along the displacement axis and an unlocked configuration in which the locking mechanism does not prevent displacement of the first platen along the displacement axis, the locking mechanism is configured to lock the first platen to the frame when the locking mechanism is in the locking configuration;
• the locking mechanism comprises a chock and a chock displacement mechanism, the chock displacement mechanism being arranged on the first platen and being connected to the chock;
• a second displacement mechanism connected to the second platen and configured to displace the second platen along the displacement axis towards the first platen the second displacement mechanism being a self-locking displacement mechanism;
• and
• at least one vertical side of the frame comprising a plurality of spaced apart recesses, the recesses being arranged such that as the first platen is displaced along the displacement axis the chock aligns with each recess of the plurality of spaced apart recesses in turn,
• wherein when the locking mechanism is in the locked configuration the chock is received in a recess of the plurality of spaced apart recesses and when the locking mechanism is in the unlocked configuration the chock is spaced apart from the recess,
• b) arranging a mould containing a material to be formed between the first and second platens;
• c) configuring the locking mechanism in the locked configuration so locking the first platen in place;
• d) displacing the second platen along the displacement axis by means of the second displacement mechanism to press the mould closed;
• e) heating the mould;
• and
• f) providing a gas to the mould to form the material in the mould.