Injection-moldable metal feedstock and method of forming metal injection-molded article

A method of forming a metal injection-moulded article comprising:

• i) injection-moulding a feedstock comprising metal powder and binder to form an injection-moulded body, said binder comprising a wax lubricant having a range of melting temperatures and an organic polymer wherein said wax lubricant comprises 15 to 25 parts by volume of paraffin wax and 20 to 30 parts by volume microcrystalline wax and the temperature of said injection-moulded body is raised at a rate not greater than 300.degree. C./hour to a holding temperature of 80.degree. C. to 120.degree. C. and is then raised at a rate of not greater than 100.degree. C./hour to a holding temperature of 200.degree. C. to 280.degree. C.;
• ii) progressively removing said wax lubricant from said injection-moulded body by raising the temperature of said body through said range of melting temperatures and sweeping liquified wax away from said injection moulded body by means of a gas stream whilst said injection-moulded body is supported on a support member which does not exert a wicking action on the liquified wax lubricant;
• iii) thermally removing said organic polymer from said injection-moulded body, and
• iv) subsequently sintering said injection-moulded body to fuse said metal powder and form said metal article.

A method of forming a metal injection-moulded article comprising:

• i) injection-moulding a feedstock comprising metal powder and binder to form an injection-moulded body, said binder comprising a wax lubricant having a range of melting temperatures and an organic polymer, wherein said binder comprises
• a) 15-25 volume % paraffin wax
• b) 20-30 volume % microcrystalline wax
• c) 45-60 volume % polyethylene
• ii) progressively removing said wax lubricant from said injection-moulded body by raising the temperature of said body through said range of melting temperatures and sweeping liquified wax away from said injection moulded body by means of a gas stream whilst said injection-moulded body is supported on a support member which does not exert a wicking action on the liquified wax lubricant;
• iii) thermally removing said organic polymer from said injection-moulded body, and
• iv) subsequently sintering said injection-moulded body to fuse said metal powder and form said metal article.