Abstract:
Adding multiple solute elements could create fracture origin through formation of intermetallic compound due to bonding of added elements. While maintaining microstructure for activating non-basal dislocation movement, additive elements not to create fracture origin, but to promote grain boundary sliding are preferably found from among inexpensive and versatile elements. Provided is Mg-based wrought alloy material including two or more among group consisting of Mn, Zr, Bi, and Sn; and Mg and unavoidable constituents, having excellent room-temperature ductility and characterized by having finer crystal grain size in Mg parent phase during room-temperature deformation and in that mean grain size in matrix thereof is 20 μm or smaller; rate of (σmax−σbk)/σmax (maximum load stress (σmax), breaking stress (σbk)) in stress-strain curve obtained by tension-compression test of the wrought material is 0.2 or higher; and resistance against breakage shows 200 kJ or higher.
Abstract:
A magnesium-based medical device which can adjust a degree of corrosion within a wide range of period such that the device can maintain a sufficient strength only during a desired period and disappears within a desired period thereafter and a manufacturing method thereof are provided. A magnesium-based medical device of the present invention is a magnesium-based medical device in which a base material is made of magnesium or a magnesium alloy, wherein a corrosion-resistant film is formed on a surface of the base material, and variation in surface hardness of the formed corrosion-resistant film in the in-plane direction is less than 21 in terms of a dispersion value of Vickers hardness.
Abstract:
Adding multiple solute elements could create fracture origin through formation of intermetallic compound due to bonding of added elements. While maintaining microstructure for activating non-basal dislocation movement, additive elements not to create fracture origin, but to promote grain boundary sliding are preferably found from among inexpensive and versatile elements. Provided is Mg-based wrought alloy material including two or more among group consisting of Mn, Zr, Bi, and Sn; and Mg and unavoidable constituents, having excellent room-temperature ductility and characterized by having finer crystal grain size in Mg parent phase during room-temperature deformation and in that mean grain size in matrix thereof is 20 μm or smaller; rate of (σmax−σbk)/σmax (maximum load stress (σmax), breaking stress (σbk)) in stress-strain curve obtained by tension-compression test of the wrought material is 0.2 or higher; and resistance against breakage shows 200 kJ or higher.
Abstract:
In order to improve the ductility or formability of a magnesium alloy, addition of rare earth elements or refinement of grain size is often used. However, conventional additional elements inhibit the action of grain boundary sliding for complementing plastic deformation. Therefore, it is required to search for additional elements that act to facilitate the grain boundary sliding not only at a conventional deformation speed but also in a higher speed range while maintaining a microstructure for activating non-basal dislocation. The present invention is to provide a wrought processed Mg-based alloy having excellent ductility at room temperature, which consists of 0.25 mass % or more to 9 mass % or less of Bi, and a balance of Mg and inevitable components, and is characterized by having an average grain size of an Mg parent phase after solution treatment and hot plastic working after casting of 20 μm or less.
Abstract:
Provided is Mg-based alloy wrought material having improved ductility, formality, and resistance against fracture. Intermetallic compounds may be formed by mutual bonding of added elements to be a fracture origin. While maintaining microstructure for activating non-basal dislocation movement of Mg-based alloy wrought material, added elements to create no fracture origin, but to promote grain boundary sliding were found from among inexpensive and versatile elements. Provided is Mg-based alloy wrought material including at least one element from Zr, Bi, and Sn and at least one element from Al, Zn, Ca, Li, Y, and Gd wherein remainder comprises Mg and unavoidable impurities; an average grain size in a parent phase is 20 μm or smaller; a value of (σmax−σbk)/σmax (maximum load stress (σmax), breaking stress (σbk)) in a stress-strain curve obtained by tension-compression tests of the wrought material is 0.2 or higher; and resistance against breakage shows 100 kJ or higher.
Abstract:
Provided is Mg-based alloy wrought material having improved ductility, formality, and resistance against fracture. Intermetallic compounds may be formed by mutual bonding of added elements to be a fracture origin. While maintaining microstructure for activating non-basal dislocation movement of Mg-based alloy wrought material, added elements to create no fracture origin, but to promote grain boundary sliding were found from among inexpensive and versatile elements. Provided is Mg-based alloy wrought material including at least one element from Zr, Bi, and Sn and at least one element from Al, Zn, Ca, Li, Y, and Gd wherein remainder comprises Mg and unavoidable impurities; an average grain size in a parent phase is 20 μm or smaller; a value of (σmax−σbk)/σmax (maximum load stress (σmax), breaking stress (σbk)) in a stress-strain curve obtained by tension-compression tests of the wrought material is 0.2 or higher; and resistance against breakage shows 100 kJ or higher.
Abstract:
A magnesium alloy of the present invention has the chemical composition that contains 0.02 mol % or more and less than 0.1 mol % of at least one element selected from yttrium, scandium, and lanthanoid rare earth elements, and magnesium and unavoidable impurities accounting for the remainder. A magnesium alloy member of the present invention is produced by hot plastic working of the magnesium alloy in a temperature range of 200° C. to 550° C., followed by an isothermal heat treatment performed in a temperature range of 300° C. to 600° C. The magnesium alloy is preferred for use in applications such as in automobiles, railcars, and aerospace flying objects. The magnesium alloy and the magnesium alloy member can overcome the yielding stress anisotropy problem, and are less vulnerable to the rising price of rare earth elements.