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.

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.

Discussed herein are systems and methods for fabrication of MgSnGe-based thermoelectric materials for applications from room temperature and near room temperature to high temperature applications. The TE materials may be fabricated by hand or ball milling a powder to a predetermined particle size and hot-pressing the milled powder to form a thermoelectric component with desired properties including a figure of merit (ZT) over a temperature range. The TE materials fabricated may be disposed in thermoelectric devices for varying applications.

A method to form a metal matrix composite reinforced with eggshell (ES). The method includes preparing an ES powder, blending and milling the ES powder with at least one metal powder selected from the group consisting of magnesium (Mg), zirconium (Zr) to form a powder mixture, compacting and sintering the powder mixture to form the metal matrix composite. In addition, a MgZr-ES metal matrix composite with improved corrosion resistance, having an amount of magnesium from 95 to 97 wt. %, an amount of zirconium from 1 to 2 wt. %, and an amount of ES from 1 to 4 wt. %, may be used for biomedical applications.

Expandable apparatus include a triggering element comprising an at least partially corrodible composite material. Methods are used to trigger expandable apparatus using such a triggering element and to form such triggering elements for use with expandable apparatus.

A magnesium-based alloy powder is made of a magnesium-based alloy that contains 0.2 mass % to 5 mass % of calcium, wherein the magnesium-based alloy powder has an average particle diameter of 100 m to 1,500 m, wherein the magnesium-based alloy powder has a particle average aspect ratio of 0.5 to 1, wherein the magnesium-based alloy powder has an apparent density of 0.2 g/cm.sup.3 to 1.2 g/cm.sup.3, and wherein the mean value of hardness variation index values obtained by dividing the difference of the maximum value and the minimum value of micro Vickers hardnesses taken at 10 measurement points in a particle cross section by the maximum value is 0.3 or less.

Expandable apparatus include a triggering element comprising an at least partially corrodible composite material. Methods are used to trigger expandable apparatus using such a triggering element and to form such triggering elements for use with expandable apparatus.

A manufacturing method for a p-type semiconductor formed by sintering a compound represented by the general chemical formula: Mg.sub.2Si.sub.XSn.sub.YGe.sub.Z (where X+Y+Z=1, X>0, and Y>0, Z>0). The p-type semiconductor has a composition in which X is in the range of 0.00<X0.25, and Z satisfies the relationship: 1.00X+0.40Z2.00X+0.10, where Z>0.00, and Y is in the range of 0.60Y0.95, and Z satisfies either of the relationships: 1.00Y+1.00Z1.00Y+0.75, where 0.60Y0.90 and Z>0.00, and 2.00Y+1.90Z1.00Y+0.75, where 0.90Y0.95 and Z>0.00.

A seal includes a metal composite that has a cellular nanomatrix that includes a metallic nanomatrix material, a metal matrix disposed in the cellular nanomatrix, and a disintegration agent; an inner sealing surface; and an outer sealing surface disposed radially from the inner sealing surface. The seal can be prepared by combining a metal matrix powder, a disintegration agent, and metal nanomatrix material to form a composition; compacting the composition to form a compacted composition; sintering the compacted composition; and pressing the sintered composition to form the seal.

The present invention provides a thermoelectric conversion material represented by the following chemical formula Mg.sub.3+mA.sub.aB.sub.bD.sub.2-eE.sub.e. The element A represents at least one selected from the group consisting of Ca, Sr, Ba and Yb. The element B represents at least one selected from the group consisting of Mn and Zn. The value of m is not less than 0.39 and not more than 0.42. The value of a is not less than 0 and not more than 0.12. The value of b is not less than 0 and not more than 0.48. The element D represents at least one selected from the group consisting of Sb and Bi. The element E represents at least one selected from the group consisting of Se and Te. The value of e is not less than 0.001 and not more than 0.06. The thermoelectric conversion material has a La.sub.2O.sub.3 crystalline structure. The thermoelectric conversion material is of n-type. The present invention provides a novel thermoelectric conversion material.