A process for additive manufacturing of a metal alloy material is provided that includes: a) providing a feedstock powder comprising base powder particles with nanoparticles attached to surfaces of the base powder particles; b) providing an additive manufacturing system with a laser power source relatively movable at a scan speed; c) wherein the additive manufacturing system has a process window for the feedstock powder; and d) exposing the feedstock powder to a predetermined power input from the laser power source at a predetermined scan speed to produce the metal alloy material. The concentration by volume of nanoparticles within the feedstock powder is such that independent first and second microstructures may be produced within the metal alloy material.

Methods for forming nanostructures of various shapes are disclosed. Nanocubes, nanowires, nanopyramids and multiply twinned particles of silver may by formed by combining a solution of silver nitrate in ethylene glycol with a solution of poly(vinyl pyrrolidone) in ethylene glycol. Hollow nanostructures may be formed by reacting a solution of solid nanostructures comprising one of a first metal and a first metal alloy with a metal salt that can be reduced by the first metal or first metal alloy. Nanostructures comprising a core with at least one nanoshell may be formed by plating a nanostructure and reacting the plating with a metal salt.

Provided are methods of producing cobalt nanoparticles (Co NPs). The methods include combining a cobalt salt, a capping agent, and a reducing agent, under Co NP synthesis conditions including a temperature selected to produce cobalt nanoparticles of a pre-selected diameter, where the temperature and pre-selected diameter are inversely related. In certain aspects, the methods further include producing hollow gold nano spheres (HGNs) using the cobalt nanoparticles as scaffolds. Also provided are cobalt nanoparticles and hollow gold nano spheres (HGNs) produced according to the present methods. Kits that find use in practicing the methods of the present disclosure are also provided.

A silver sintering preparation in the form of a silver sintering paste comprising 70 to 95 wt.-% of coated silver particles (A) and 5 to 30 wt.-% of organic solvent (B) or in the form of a silver sintering preform comprising 74.5 to 100 wt.-% of coated silver particles (A) and 0 to 0.5 wt.-% of organic solvent (B), wherein the coating of the coated silver particles (A) comprises silver acetylacetonate (silver 2,4-pentanedionate) and/or at least one silver salt of the formula C.sub.nH.sub.2n+1COOAg with n being an integer in the range of 7 to 10, and wherein the at least one silver salt is thermally decomposable at >160° C.

The present disclosure provides a method for preparing a powder material and an application thereof. The preparation method includes: obtaining an initial alloy ribbon including a matrix phase and a dispersed particle phase by solidifying an alloy melt, and then removing the matrix phase in the initial alloy ribbon while retaining the dispersed particle phase, so as to obtain a powder material composed of original dispersed particle phase. The preparation method of the present disclosure is simple in process and can prepare multiple powder materials of nano-level, sub-micron-level and micro-level. The powder materials have good application prospects in the fields such as catalytic materials, powder metallurgy, composite materials, wave-absorbing materials, sterilization materials, metal injection molding, 3D printing and coating.

The present disclosure provides compositions and methods for printing three-dimensional (3D) objects. A composition for 3D printing may comprise a polymeric precursor configured to form a polymeric material, wherein the polymeric material is configured to decompose at a first temperature. The composition may further comprise a photoinitiator configured to initiate formation of the polymeric material from the polymeric precursor when exposed to photoradiation. The composition may further comprise a plurality of particles comprising a first metal. The composition may further comprise a soluble metallic precursor compound configured to react at a second temperature to form a plurality of nanoparticles comprising a second metal capable of alloying with the first metal.

A three-dimensional chiral nanostructure according to an embodiment of the present invention comprises: metal nanoparticles having a chiral structure: and a coating layer enclosing the metal nanoparticles. The metal nanoparticle is formed in a polyhedral structure having an R region and an S region in which atoms are arranged clockwise and counterclockwise, respectively, in the order of (111), (100), and (110) crystal faces on the basis of the chiral center, wherein at least a portion of the edges form a curve tilting and extending from the R or S region so that the metal nanoparticle has a chiral structure.

A method for producing nanoparticulate compressed tablets/pellets from synthetic and/or natural materials, and compressed tablets/pellets produced using the method for producing nanoparticulate compressed tablets/pellets from synthetic and/or natural materials and to uses thereof.

Disclosed is a method for preparing silver-copper mixed powder having a core-shell structure. The method includes: dissolving silver (Ag) and copper (Cu) in an aqueous nitric acid solution; adding a reducing agent to the solution; and preparing silver-copper mixed powder having a core-shell structure by performing plasma post-treatment, after performing the adding the reducing agent to the solution.

A method is provided for producing a bonding composition containing copper particles and a second liquid medium. In this production method, the copper particles are produced in a first liquid medium using a wet reduction method, and thus a dispersion of the copper particles is prepared. Subsequently, the first liquid medium in the dispersion is ultimately, finally or eventually replaced with the second liquid medium while the dispersion is kept wet. It is also preferable that the first liquid medium is replaced with another liquid medium one or more times, and the second liquid medium is used in the final replacement. The liquid media are preferably replaced at a temperature of lower than 100° C. The second liquid medium preferably includes one or more of water, alcohol, ketone, ester, ether, and hydrocarbon.