Identifying a stable phase of a binary alloy comprising a solute element and a solvent element. In one example, at least two thermodynamic parameters associated with grain growth and phase separation of the binary alloy are determined, and the stable phase of the binary alloy is identified based on the first thermodynamic parameter and the second thermodynamic parameter, wherein the stable phase is one of a stable nanocrystalline phase, a metastable nanocrystalline phase, and a non-nanocrystalline phase. In different aspects, an enthalpy of mixing of the binary alloy may be calculated as a first thermodynamic parameter, and an enthalpy of segregation of the binary alloy may be calculated as a second thermodynamic parameter. In another example, a diagram delineating a plurality of regions respectively representing different stable phases of at least one binary alloy is employed, wherein respective regions of the plurality of regions are delineated by at least one boundary determined as a function of at least two thermodynamic parameters associated with grain growth and phase separation of the at least one binary alloy.

Disclosed is an AMS process using a water-leachable alloy that reacts with water and dissolves, and a porous metal manufactured using the same. An AMS precursor including element groups that are selected in consideration of the relationship of heat of mixing with the water-leachable alloy composition to be subjected to the AMS process is immersed in the alloy melt, thus manufacturing a bi-continuous structure alloy. The bi-continuous structure alloy is subjected to dealloying using water, thus manufacturing the porous metal. The water-leachable alloy is a Ca-based alloy having high reactivity to water and high oxidation resistance at high temperatures, and a dealloying process thereof is performed using only pure water, unlike a conventional dealloying process performed using a toxic etching solution of a strong acid/strong base. The metal porous body has high elongation, a large surface area, and low thermal conductivity.

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a -MnAl phase and crystal grains containing a 2-MnAl phase. Assuming that the area of the crystal grains containing the -MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the 2-MnAl phase therein is A, the value of B/A is 0.2 or more and 21.0 or less. When the ratio of the areas between the crystal grains containing the -MnAl phase and those containing the 2-MnAl phase is controlled within the above range, metamagnetism is imparted to the MnAl alloy and, thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of 100 C. to 200 C.

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a -MnAl phase and crystal grains containing a 2-MnAl phase. Assuming that the area of the crystal grains containing the -MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the 2-MnAl phase therein is A, the value of B/A is 0.2 or more and 21.0 or less. When the ratio of the areas between the crystal grains containing the -MnAl phase and those containing the 2-MnAl phase is controlled within the above range, metamagnetism is imparted to the MnAl alloy and, thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of 100 C. to 200 C.

A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a -MnAl phase and crystal grains containing a 2-MnAl phase and a -MnAl phase. When the ratio of the -MnAl phase is A, 75%A99% is preferably satisfied, and when the ratios of the 2-MnAl phase and -MnAl phase are B and C, respectively, B<C is preferably satisfied. Thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of 100 C. to 200 C. and to enhance saturation magnetization.

A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a -MnAl phase and crystal grains containing a 2-MnAl phase and a -MnAl phase. When the ratio of the -MnAl phase is A, 75%A99% is preferably satisfied, and when the ratios of the 2-MnAl phase and -MnAl phase are B and C, respectively, B<C is preferably satisfied. Thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of 100 C. to 200 C. and to enhance saturation magnetization.

A method of increasing volume ratio of magnetic particles in a MnBi alloy includes depositing a MnBi alloy powder containing magnetic particles and non-magnetic particles on a sloped surface having a magnetic field acted thereupon. The method further includes collecting falling non-magnetic particles while separated magnetic particles are magnetically retained on the sloped surface.

A method of increasing volume ratio of magnetic particles in a MnBi alloy includes depositing a MnBi alloy powder containing magnetic particles and non-magnetic particles on a sloped surface having a magnetic field acted thereupon. The method further includes collecting falling non-magnetic particles while separated magnetic particles are magnetically retained on the sloped surface.

A 2-step high temperature process for recovering Ni, Co, and Mn from various sources comprises preparing a metallurgical charge comprising materials containing Ni, Co, and Mn, and Si, Al, Ca and Mg as slag formers; smelting the charge with slag formers in first reducing conditions, thereby obtaining a NiCo alloy comprising a major part of at least one of Co and Ni, with Si<0.1%, and a first slag comprising the major part of the Mn; separation of the first slag from the alloy; and, smelting the first slag in second reducing conditions, more reducing than said first reducing conditions, thereby obtaining a SiMn alloy comprising the major part of the Mn, with Si>10%, and a second slag. A NiCo alloy is produced, and a SiMn alloy is produced. The second slag is essentially free of heavy metals and therefore suitable for reuse.

A 2-step high temperature process for recovering Ni, Co, and Mn from various sources comprises preparing a metallurgical charge comprising materials containing Ni, Co, and Mn, and Si, Al, Ca and Mg as slag formers; smelting the charge with slag formers in first reducing conditions, thereby obtaining a NiCo alloy comprising a major part of at least one of Co and Ni, with Si<0.1%, and a first slag comprising the major part of the Mn; separation of the first slag from the alloy; and, smelting the first slag in second reducing conditions, more reducing than said first reducing conditions, thereby obtaining a SiMn alloy comprising the major part of the Mn, with Si>10%, and a second slag. A NiCo alloy is produced, and a SiMn alloy is produced. The second slag is essentially free of heavy metals and therefore suitable for reuse.