The present invention relates to granular composite density enhancement, and related methods and compositions. The application where the properties are valuable include but are not limited to: 1) additive manufacturing (“3D printing”) involving metallic, ceramic, cermet, polymer, plastic, or other dry or solvent-suspended powders or gels, 2) concrete materials, 3) solid propellant materials, 4) cermet materials, 5) granular armors, 6) glass-metal and glass-plastic mixtures, and 7) ceramics comprising (or manufactured using) granular composites.

In some examples, a controller is to receive a measurement of an electrical property of an oscillation control system from a sensor, determine, based on the measurement of the electrical property, a frequency of oscillation of a structure vibrated by the oscillation control system in the system, the vibration of the structure to cause passage of a portion of a material through the structure, and estimate a level of a remaining portion of the material at the structure based on the determined frequency of oscillation of the structure.

In some examples, a method measures values of a property of a build material aged in a heated environment, and computes, using a predictive model for each of a plurality of recyclability ratios, output values of the property over a plurality of generations of the build material, each recyclability ratio of the plurality of recyclability ratios representing relative amounts of fresh build material and used build material. The method further includes presenting the output values of the property over the plurality of generations to enable selection of a recyclability ratio to use in building a part using the build material.

A method of determining a tool path for an additive deposition on a surface, the method including receiving primary edges data of the surface of a three-dimensional (3D) object; calculating a number of raster lines for applying an additive deposition on the surface; mapping a raster pattern to the surface of the 3D object; calculating surface normal and rotational angles along the raster lines; calculating a nozzle velocity of an additive application used for producing the additive deposition on the surface; identifying curvature effects of the 3D object; and establishing an order of performing passes of the additive deposition on the surface based on a selected direction for performing the additive deposition and a consideration of a residual stress profile of a resulting deposit.

A method of determining a tool path for an additive deposition on a surface, the method including receiving primary edges data of the surface of a three-dimensional (3D) object; calculating a number of raster lines for applying an additive deposition on the surface; mapping a raster pattern to the surface of the 3D object; calculating surface normal and rotational angles along the raster lines; calculating a nozzle velocity of an additive application used for producing the additive deposition on the surface; identifying curvature effects of the 3D object; and establishing an order of performing passes of the additive deposition on the surface based on a selected direction for performing the additive deposition and a consideration of a residual stress profile of a resulting deposit.

A 4D printing method for a titanium-nickel shape memory alloy, and the titanium-nickel shape memory alloy and application thereof. Pure titanium and pure nickel are mixed and smelted, and titanium-nickel alloy bars are obtained; then alloy powder is prepared by means of a rotating electrode atomization method, the powder is sieved, and titanium-nickel alloy powder having a grain size of 15-53 μm is obtained; and the obtained titanium-nickel alloy powder is placed in a discharge plasma auxiliary ball mill to be subjected to discharge treatment, the powder is subjected to surface modification, and finally the titanium-nickel shape memory alloy is formed by means of SLM forming. The phase composition of the titanium-nickel shape memory alloy is composed of a B2 austenite phase of a CsCl type structure, a B19′ Martensite phase of a monocline structure and a Ti.sub.2Ni precipitated phase. The microstructure of the memory alloy comprises nano-sized cellular-like crystals and micron-sized dendritic crystals, and the cellular-like crystals and the dendritic crystals are alternately distributed in a layered manner. The memory alloy has the characteristics of being unique in structure, nearly fully dense and ultrahigh in performance.

The present invention belongs to the field of additive manufacturing technology, and discloses a 4D printing method capable of in-situ regulating functional properties of nickel-titanium (NiTi) alloys and the application thereof. The method comprises the following steps: subjecting NiTi alloy bars to atomization milling to obtain NiTi alloy powder with a particle size of 15-53 μm, placing the NiTi alloy powder in a discharge plasma assisted ball mill for discharge treatment to promote the activation of powder activity, then adding nano-sized Ni powder with a particle size of 100-800 nm to obtain mixed powder, then continuing the discharge treatment to realize the metallurgical bonding between the NiTi alloy powder and the nano-sized Ni powder to obtain the modified powder, and finally using the additive manufacturing technology to prepare and form the modified powder into a functionalized NiTi alloy. The present invention achieves the metallurgical bonding between the nano-sized Ni powder and the large-sized spherical NiTi alloy powder by adding the nano-sized Ni powder in the process of discharge treatment, which is conducive to preparing a bulk alloy with uniform composition, structure and properties and the parts made therewith.

An additive manufacturing method may involve: Providing a first material in powder form and a second material as a consumable electrode; forming the first material into a first layer on a base; placing an end of the second material in close proximity to a portion of the first layer; operating a power supply connected to the base and the second material to provide electrical energy sufficient to initiate a chemical reaction between the first and second materials and form a reaction product; feeding additional amounts of the second material while moving the end of the second material along a desired pattern adjacent the first layer, additional reaction products forming additional portions of the article; providing additional quantities of the first material over the first layer to form a subsequent layer; and operating the power supply to form additional portions of the article in the subsequent layer.

Three dimensional “green” parts are formed by combining sheet layers comprising metal powder bound together by a polymer. The “green” parts are then sintered to drive off the polymer and consolidate the metal powder to produce a monolithic metal part. Particularly, the invention is directed to processes for forming and stacking the shaped sheet layers that are readily automated and preserve the high value powder metal and polymer sheet trim scrap for reuse resulting in an additive overall process with little material waste. The invention includes processes in which “green” elements formed by methods such as three dimensional printing are incorporated into the “green” stack and become an integral part of the final sintered part. It further includes processes in which “green” sheet layers are shaped by methods such as hot bending or vacuum forming to provide three dimensional part features.

Three dimensional “green” parts are formed by combining sheet layers comprising metal powder bound together by a polymer. The “green” parts are then sintered to drive off the polymer and consolidate the metal powder to produce a monolithic metal part. Particularly, the invention is directed to processes for forming and stacking the shaped sheet layers that are readily automated and preserve the high value powder metal and polymer sheet trim scrap for reuse resulting in an additive overall process with little material waste. The invention includes processes in which “green” elements formed by methods such as three dimensional printing are incorporated into the “green” stack and become an integral part of the final sintered part. It further includes processes in which “green” sheet layers are shaped by methods such as hot bending or vacuum forming to provide three dimensional part features.