Cylinder head for engine

A cylinder head for an internal combustion engine comprised of a main cylinder head body formed from a first material, said main cylinder head body being formed with a surface adapted to be in facing relationship to a cylinder block for closing a cylinder bore formed therein, a recess in said main cylinder head body surrounded by said surface, a flow passage extending through said cylinder head body between said recess and an external surface of said main cylinder head body, and a valve seat formed at the recess end of said flow passage by an insert formed from a second material comprising a Sintered ferrous alloy metallurgically bonded by plastic deformation to said main cylinder head body, said first material comprising an aluminum alloy having a 0.2% yield strength at 400.degree. C. less than 45 Mpa for establishing plastic flow thereof during the bonding process to avoid significant melting thereof during the bonding process.

A cylinder head for an internal combustion engine comprised of a main cylinder head body formed from a first material, said main cylinder head body being formed with a surface adapted to be in facing relationship to a cylinder block for closing a cylinder bore formed therein, a recess in said main cylinder head body surrounded by said surface, a flow passage extending through said cylinder head body between said recess and an external surface of said main cylinder head body, and a valve seat formed at the recess end of said flow passage by an insert formed from a second material comprising a Sintered ferrous alloy metallurgically bonded by elastic deformation to said main cylinder head body, said first material comprising an aluminum alloy having a 0.2% yield strength at 400.degree. C. less than 45 Mpa for establishing plastic flow thereof during the bonding process to avoid significant melting thereof during the bonding process.

A cylinder head for an internal combustion engine comprised of a main cylinder head body formed from a first material, said main cylinder head body being formed with a surface adapted to be in facing relationship to a cylinder block for closing a cylinder bore formed therein, a recess in said main cylinder head body surrounded by said surface, a flow passage extending through said cylinder head body between said recess and an external surface of said main cylinder head body, and a valve seat formed at the recess end of said flow passage by an insert formed from a Sintered ferrous alloy metallurgically bonded by plastic deformation to said main cylinder head body by a process including electrical resistance heating, said first material comprising an aluminum alloy and having an electrical resistivity of less than 8.5 m.times.10.sup.-2 .mu..OMEGA. for limiting the temperature attained during the bonding process to avoid significant melting thereof during the bonding process.