A magnesium alloy structural member includes an alloy substrate that includes a sheet-shaped portion consisting of a magnesium alloy corresponding to an AZ91 alloy under the standards of American Society for Testing and Materials. The alloy substrate has a surface, a part of which is a mirror-finished portion having a surface roughness Ra of less than 0.3 μm.

A method includes positioning a cylindrical tool having one or more rows of blades within a cylindrical bore having a surface, forming annular grooves and peaks into the surface with the grooving blades when the swaging blades are in the retracted position, and translating the swaging blades from the retracted position to the extended position to deform the peaks. The one or more rows of blades includes fixed grooving blades and translatable swaging blades having retracted and extended positions.

A surface roughening tool includes a cylindrical body and at least one grooving blade outwardly radially projecting from the body and configured to form grooves and peaks into a surface. The surface roughening tool also includes at least one swaging blade outwardly radially projecting from the body and configured to deform the peaks. The at least one swaging blade is aligned with the at least one grooving blade along a circumference of the body.

A method includes positioning a cylindrical tool having one or more rows of blades within a cylindrical bore having a surface, forming annular grooves and peaks into the surface with the grooving blades when the swaging blades are in the retracted position, and translating the swaging blades from the retracted position to the extended position to deform the peaks. The one or more rows of blades includes fixed grooving blades and translatable swaging blades having retracted and extended positions.

According to one aspect of this disclosure, a grooving tool is provided. The grooving tool has a body with a plurality of recesses. Plural inserts assembled into each of the recesses. The recesses include a cutting edge for forming grooves in an engine cylinder wall when rotated in one rotational direction. The insert also includes a peening surface extending in the opposite rotational direction from the cutting edge for deforming the upper edges of the grooves when rotated in an opposite rotational direction.

A surface roughening tool includes a cylindrical body and at least one grooving blade outwardly radially projecting from the body and configured to form grooves and peaks into a surface. The surface roughening tool also includes at least one swaging blade outwardly radially projecting from the body and configured to deform the peaks. The at least one swaging blade is aligned with the at least one grooving blade along a circumference of the body.

According to one aspect of this disclosure, a grooving tool is provided. The grooving tool has a body with a plurality of recesses. Plural inserts assembled into each of the recesses. The recesses include a cutting edge for forming grooves in an engine cylinder wall when rotated in one rotational direction. The insert also includes a peening surface extending in the opposite rotational direction from the cutting edge for deforming the upper edges of the grooves when rotated in an opposite rotational direction.