A bioabsorbable implant including an elongated metallic element having more than 50% by weight a metal and being substantially free of rare earth elements, the elongated metallic element defining at least a portion of the bioabsorbable implant and including a wire formed into a discrete bioabsorbable expandable metal ring; at least two biostable ring elements, each biostable ring element having a biostable and radio-opaque metallic alloy, the bioabsorbable expandable metal ring being disposed adjacent to at least one of the biostable ring elements; at least one flexible longitudinal connector including a bioabsorbable polymer, the connector being disposed between at least two adjacent rings; and a coating having at least one pharmaceutically active agent disposed over at least a portion of one ring.

A magnesium alloy containing, in % by mass, 0.95 to 2.00% of Zn, 0.05% or more and less than 0.30% of Zr, 0.05 to 0.20% of Mn, and the balance consisting of Mg and unavoidable impurities, wherein the magnesium alloy has a particle size distribution with an average crystal particle size from 1.0 to 3.0 μm and a standard deviation of 0.7 or smaller.

Provided is a frac plug or the like capable of being inserted into a borehole to seal the borehole with high strength, and then quickly disassembled and removed, thereby efficiently producing petroleum. A frac plug according to the present embodiment has a member made of a magnesium (Mg) alloy. The member has a multi-phase structure including a first phase, which is a matrix phase, and a second phase present in the first phase. In the multi-phase structure, the second phase is distributed in a substantially striped pattern in the first phase in a first cross section perpendicular to a second direction of the frac plug, and distributed in a substantially mesh-like pattern in the first phase in a second cross section perpendicular to a first direction of the frac plug.

The disclosure discloses a high-speed spinning magnesium alloy and a preparation method thereof, the magnesium alloy has Mg-AI-Zn-Mn-Sr alloy with a high formability and high strength, and its chemical composition mass percentage is: Al: 2.4-4.5 wt.%; Zn: 0.6-1.2 wt.%; Mn: 0.4-0.6 wt.%; Sr: 0.15-0.3 wt.%; the balance is Mg. The present disclosure adopts the principle that by increasing the content of Mn in the magnesium alloy, a large amount of Mn-rich phase is generated during the alloy preparation process, and the degree of subcooling is controlled so that a fine spherical dispersed nano-scale Mn-rich phase is obtained during the solidification process. The nano-scale Mn-rich precipitate phase can pin the grain boundaries and inhibit the grain boundary migration to refine grains and achieve the effect of improving the strength. The divorced eutectic Mg.sub.17Al.sub.12 phase generated during the casting process will deteriorate the structure, so Sr is added to the alloy, Sr combining with Al to suppress the coarse phase of divorced eutectic Mg.sub.17Al.sub.12, refine the grains, increase the amount of eutectic, and reduce the risk of thermal cracking of large-size cast bars. In addition, Sr weakens the texture during the high-temperature spinning forming process and reduces the risk of cracking during the spinning tension, which is beneficial to high-speed spinning forming.

The disclosure discloses a high-speed spinning magnesium alloy and a preparation method thereof, the magnesium alloy has Mg-AI-Zn-Mn-Sr alloy with a high formability and high strength, and its chemical composition mass percentage is: Al: 2.4-4.5 wt.%; Zn: 0.6-1.2 wt.%; Mn: 0.4-0.6 wt.%; Sr: 0.15-0.3 wt.%; the balance is Mg. The present disclosure adopts the principle that by increasing the content of Mn in the magnesium alloy, a large amount of Mn-rich phase is generated during the alloy preparation process, and the degree of subcooling is controlled so that a fine spherical dispersed nano-scale Mn-rich phase is obtained during the solidification process. The nano-scale Mn-rich precipitate phase can pin the grain boundaries and inhibit the grain boundary migration to refine grains and achieve the effect of improving the strength. The divorced eutectic Mg.sub.17Al.sub.12 phase generated during the casting process will deteriorate the structure, so Sr is added to the alloy, Sr combining with Al to suppress the coarse phase of divorced eutectic Mg.sub.17Al.sub.12, refine the grains, increase the amount of eutectic, and reduce the risk of thermal cracking of large-size cast bars. In addition, Sr weakens the texture during the high-temperature spinning forming process and reduces the risk of cracking during the spinning tension, which is beneficial to high-speed spinning forming.

Provided is a magnesium alloy in which Cu content is 0 to 1.5% by mass, Ni content is 0 to 0.5% by mass, Ca content is 0.05 to 1.0% by mass, Al content is 0 to 0.5% by mass, Zn content is 0 to 0.3% by mass, Mn content is 0 to 0.3% by mass, Zr content is 0 to 0.3% by mass, the total of the Cu content and the Ni content being 0.005% by mass to 2.0% by mass, and the balance being magnesium and unavoidable impurities.

Provided is a magnesium alloy in which Cu content is 0 to 1.5% by mass, Ni content is 0 to 0.5% by mass, Ca content is 0.05 to 1.0% by mass, Al content is 0 to 0.5% by mass, Zn content is 0 to 0.3% by mass, Mn content is 0 to 0.3% by mass, Zr content is 0 to 0.3% by mass, the total of the Cu content and the Ni content being 0.005% by mass to 2.0% by mass, and the balance being magnesium and unavoidable impurities.

A castable, moldable, or extrudable magnesium-based alloy that includes one or more insoluble additives. The insoluble additives can be used to enhance the mechanical properties of the structure, such as ductility and/or tensile strength. The final structure can be enhanced by heat treatment, as well as deformation processing such as extrusion, forging, or rolling, to further improve the strength of the final structure as compared to the non-enhanced structure. The magnesium-based composite has improved thermal and mechanical properties by the modification of grain boundary properties through the addition of insoluble nanoparticles to the magnesium alloys. The magnesium-based composite can have a thermal conductivity that is greater than 180 W/m-K, and/or ductility exceeding 15-20% elongation to failure.

A castable, moldable, or extrudable magnesium-based alloy that includes one or more insoluble additives. The insoluble additives can be used to enhance the mechanical properties of the structure, such as ductility and/or tensile strength. The final structure can be enhanced by heat treatment, as well as deformation processing such as extrusion, forging, or rolling, to further improve the strength of the final structure as compared to the non-enhanced structure. The magnesium-based composite has improved thermal and mechanical properties by the modification of grain boundary properties through the addition of insoluble nanoparticles to the magnesium alloys. The magnesium-based composite can have a thermal conductivity that is greater than 180 W/m-K, and/or ductility exceeding 15-20% elongation to failure.

The present disclosure provides a magnesium alloy and a preparation method and an application thereof. Based on the total weight of the magnesium alloy, the magnesium alloy includes 0.8-1.4 wt % of rare earth element, 0.01-0.2 wt % of R, 0.8-1.5 wt % of Mn, 0-0.01 wt % of Fe, 0-0.01 wt % of Cu, 0-0.01 wt % of Ni, 0-0.01 wt % of Co, 0-0.01 wt % of Sn, 0-0.01 wt % of Ca, and 96.84-98.39 wt % of Mg, wherein R is at least one selected from Al and Zn.