An extrusion forming apparatus includes a mold disposed in a front open end of an extruding channel of a housing, a holding seat disposed in front of the front open end and partially extending into the extruding channel to abut the mold, and a vibrating source connected to the housing in abutment with the holding seat and controllable to apply an ultrasonic energy to the mold through the holding seat. An extrusion forming method is carried out by the extrusion forming apparatus. An extruded product is made by the extrusion forming method using the extrusion forming apparatus.

A raw material of aluminum base alloy is extruded and formed by using a forming pattern comprising an upper pattern having plural through-holes for supplying the raw material into diaphragms of equal angles on the circumference and circular cylindrical protrusions positioned in the center of plural through-holes so as to be surrounded by plural through-holes at the exit side of the through-holes, and a lower pattern positioned in the concave portions commonly penetrating at the exit of the plural through-holes of the upper pattern, having through-holes for inserting the protrusions of circular circumference of the upper pattern by providing a tube forming gap, positioned in the center of concave portions of the concave portions in the circular columnar shape of the upper pattern.

[Problem] To present a small-diameter magnesium base alloy tube and its manufacturing method of long length, high dimensional precision, and excellent mechanical properties.

[Solving Means] A raw material 1 of aluminum base alloy is extruded and formed by using a forming pattern comprising an upper pattern 2 having plural through-holes 21 for supplying the raw material into diaphragms of equal angles on the circumference and circular cylindrical protrusions 22 positioned in the center of plural through-holes 21 so as to be surrounded by plural through-holes 21 at the exit side of the through-holes 21, and a lower pattern 3 positioned in the concave portions commonly penetrating at the exit of the plural through-holes 21 of the upper pattern 2, having through-holes 32 for inserting the protrusions of circular circumference of the upper pattern by providing a tube forming gap, positioned in the center of concave portions 31 of the concave portions 31 in the circular columnar shape of the upper pattern 2.

In the context of a method for producing a profile on a plastically deformable, preferably cylindrical, workpiece by axial forming, a relative movement between a shaping tool profile provided on a forming tool and the workpiece to be formed is carried out during a forming process in order to produce a workpiece-side profile having a workpiece-side profile length. During the relative movement between the shaping tool profile and the workpiece to be formed, an oscillating relative movement between the shaping tool profile and the workpiece to be formed is created, in which a forming stroke and a return stroke in the opposite direction to the forming stroke are alternately carried out. The forming process in progress is varied with respect to the oscillating relative movement. A mechanical arrangement is designed to carry out the aforementioned method.