Base material for screw, screw, and method for producing same
AssigneeMaruemu Works Co., Ltd.
InventorsShigeru YAMANAKA, Ryo SHINOHARA, Kenji FUKUDA
Life of this patent
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Abstract
The present invention provides a pure titanium screw or a base material for a pure titanium screw having sufficient strength comparable to that of titanium alloys. The present invention provides a substantially cylindrical pure titanium screw base material or screw, wherein the maximum value of the specific strength in the orientation of the (1 0 −1 0) plane in the axial direction of the substantially cylindrical shape is 3 or more, and the hardness of a center part and the hardness of an outer peripheral part in a substantially circular cross section orthogonal to the axial direction are approximately the same.
Claims21
A base material for a screw having a substantially cylindrical shape or a screw having a substantially cylindrical shape, wherein each of the base material and the screw is made of pure titanium, each of the base material and the screw has 3 or more of a maximum specific intensity of the orientation in the (1 0−1 0) plane in the axial direction of the substantially cylindrical shape, and a hardness of a central part and a hardness of a peripheral part in a substantially circular cross section perpendicular to the axial direction are substantially same.
A method for producing a base material for a screw, comprising the steps of:
- (I) preparing a pure titanium material having a substantially cylindrical shape and a cross-sectional area of A0;
- and
- (II) swaging the pure titanium material, to obtain the base material for the screw, which has a substantially cylindrical shape having a cross-sectional area of A1 after swaging and a true strain represented by ln(A0/A1) of 2 or more, wherein the maximum value of the specific intensity of the orientation of the (1 0 −1 0) plane in the axial direction of the substantially cylindrical shape is 3 or more, and a hardness of a central part and a peripheral part in a substantially circular cross section perpendicular to the axial direction are substantially same.
A method for producing a base material for a screw, consisting of the steps of:
- (I) preparing a pure titanium material having a substantially cylindrical shape and a cross-sectional area of A0;
- and
- (II) swaging the pure titanium material, to obtain the base material for the screw, which has a substantially cylindrical shape having a cross-sectional area of A1 after swaging and a true strain represented by ln(A0/A1) of 2 or more, wherein the maximum value of the specific intensity of the orientation of the (1 0 −1 0) plane in the axial direction of the substantially cylindrical shape is 3 or more, and a hardness of a central part and a peripheral part in a substantially circular cross section perpendicular to the axial direction are substantially same.
-25. (canceled)
Dependencies are inferred from the claim text.