Abstract: A new spray process allows for deposition below a critical velocity limit of cold spray, while providing adhesion. Post deposition heat treatment has shown excellent coating strength. A wide variety of materials can be deposited. The spray process is based on ShockWave Induced Spraying (SWIS) but with much slower spray jet projection velocities. High porosity, pore size control, and porosity control are demonstrated to be controllable. Preheating of feedstock and uniform temperature of the SWIS delivery allow for the deposition below critical velocity.

Abstract: A method of forming a hollow structure in an additively manufactured object involves creating a pattern on a surface of a base material of the object with a sacrificial metal filler having a melting point of 350° C. or less, the pattern defining a shape of the hollow structure on the base material. A metal layering material is cold sprayed over the sacrificial metal filler and at least a portion of the base material. The sacrificial metal filler is removed from the pattern by melting the sacrificial metal filler without melting or deforming the base material or the metal layering material to leave the hollow structure in the object formed from the pattern. Non-standard cold spray conditions are used with the metal layering material to prevent damage and or displacement of the filler while still forming a coating of the metal layering material on the filler and base material.

Abstract: A new spray process allows for deposition below a critical velocity limit of cold spray, while providing adhesion. Post deposition heat treatment has shown excellent coating strength. A wide variety of materials can be deposited. The spray process is based on ShockWave Induced Spraying (SWIS) but with much slower spray jet projection velocities. High porosity, pore size control, and porosity control are demonstrated to be controllable. Preheating of feedstock and uniform temperature of the SWIS delivery allow for the deposition below critical velocity.

Abstract: A technique for improving cold spray deposition conditions for cold spray additive manufacture of parts involves providing an in-situ temperature feedback controller with a remote instantaneous temperature sensor supplying surface temperature measurements of the deposition surface, and a (preferably long pulse) laser for heating. Temperature feedback allows for control over deposition conditions yielding predictable deposition properties.

Abstract: A method for enabling cold spray of steels, particularly transformation hardenable steels including tool steels, has been made possible by: heat treating steel powder while agitating the powder to limit agglomeration and particle growth; cooling it slowly enough to avoid retransformation hardening; and protecting the powder from cold working or retransformation hardening until cold sprayed. Surprisingly the softening, as well as the agglomerated morphology of powders, has been found to allow for deposition of steel powders. Furthermore, the cooling has been found to be possible within 8 hour heat treatments, and high density, and reasonably high deposition efficiencies have been achieved. Water- and gas-atomized starting powders have been treated and cold sprayed.

Abstract: A method of forming a hollow structure in an additively manufactured object involves creating a pattern on a surface of a base material of the object with a sacrificial metal filler having a melting point of 350° C. or less, the pattern defining a shape of the hollow structure on the base material. A metal layering material is cold sprayed over the sacrificial metal filler and at least a portion of the base material. The sacrificial metal filler is removed from the pattern by melting the sacrificial metal filler without melting or deforming the base material or the metal layering material to leave the hollow structure in the object formed from the pattern. Non-standard cold spray conditions are used with the metal layering material to prevent damage and or displacement of the filler while still forming a coating of the metal layering material on the filler and base material.

Abstract: A method for applying a coating to a substrate surface is provided. The method involves cold spraying a coating material against the surface of the substrate at a first velocity. The first velocity is lower in magnitude than a critical velocity. The method also involves cold spraying the coating material against the surface of the substrate at a second velocity. The second velocity is greater in magnitude than the critical velocity. The critical velocity is a threshold velocity below which the coating material is substantially deflected by the surface of the substrate and above which the coating material substantially adheres to the surface of the substrate.

Abstract: A wear resistant friction coating (WRFC) can be applied on a lightweight metallic substrate, by applying a cold gas dynamic spray bond coat containing more iron than any other single element directly onto a surface of the substrate, and thermal spraying the WRFC coating over the bond coat to a thickness of at least 500 ?m. Corrosion resistance, adhesion, thermal cycling resistance, and wear resistance have been demonstrated.

Abstract: A powder fluidizing system, comprising a pressure vessel, a powder container removably mounted within the pressure vessel, and comprising a bottom sieve; a vibrator generating vibrations and transmitting the vibrations to the powder container above the sieve; and a guide directly secured under said powder container to the bottom sieve; wherein a bulk powder fed within the powder container is vibrated within the powder container and flows through the sieve to the guide, and a powder fluidizing method, comprising feeding a bulk powder within a powder reservoir maintained under pressure; vibrating the powder reservoir; and passing the powder through a sieve positioned at the bottom of the powder reservoir.

Abstract: A method for applying a coating to a substrate surface is provided. The method involves cold spraying a coating material against the surface of the substrate at a first velocity. The first velocity is lower in magnitude than a critical velocity. The method also involves cold spraying the coating material against the surface of the substrate at a second velocity. The second velocity is greater in magnitude than the critical velocity. The critical velocity is a threshold velocity below which the coating material is substantially deflected by the surface of the substrate and above which the coating material substantially adheres to the surface of the substrate.

Abstract: A method for applying a coating to a substrate surface is provided. The method involves cold spraying a coating material against the surface of the substrate at a first velocity. The first velocity is lower in magnitude than a critical velocity. The method also involves cold spraying the coating material against the surface of the substrate at a second velocity. The second velocity is greater in magnitude than the critical velocity. The critical velocity is a threshold velocity below which the coating material is substantially deflected by the surface of the substrate and above which the coating material substantially adheres to the surface of the substrate.

Abstract: A method for applying a coating to a substrate surface is provided. The method involves cold spraying a coating material against the surface of the substrate at a first velocity. The first velocity is lower in magnitude than a critical velocity. The method also involves cold spraying the coating material against the surface of the substrate at a second velocity. The second velocity is greater in magnitude than the critical velocity. The critical velocity is a threshold velocity below which the coating material is substantially deflected by the surface of the substrate and above which the coating material substantially adheres to the surface of the substrate.

Abstract: A powder fluidizing system, comprising a pressure vessel, a powder container removably mounted within the pressure vessel, and comprising a bottom sieve; a vibrator generating vibrations and transmitting the vibrations to the powder container above the sieve; and a guide directly secured under said powder container to the bottom sieve; wherein a bulk powder fed within the powder container is vibrated within the powder container and flows through the sieve to the guide, and a powder fluidizing method, comprising feeding a bulk powder within a powder reservoir maintained under pressure; vibrating the powder reservoir; and passing the powder through a sieve positioned at the bottom of the powder reservoir.

Abstract: A method for producing nanostructured coatings on a substrate, comprising: preparing a nanocrystalline powder of a powder size comprised between 1 and 60 ?m; and combining cleaning the surface of the substrate and cold spraying the nanocrystalline powder on the surface of the substrate, and a system for producing nanocrystalline coatings on a substrate, comprising a spray head, a cleaning head and a handling system monitoring the spray head and the cleaning head relative to the substrate to be coated, the spray head being a first cold spray head, the first cold spray head depositing on the substrate at least one nanocrystalline powder, the cleaning head optimizing the surface being coated with the at least one layer of nanocrystalline powder.

Abstract: A method for producing nanostructured coatings on a substrate, comprising: preparing a nanocrystalline powder of a powder size comprised between 1 and 60 ?m; and combining cleaning the surface of the substrate and cold spraying the nanocrystalline powder on the surface of the substrate, and a system for producing nanocrystalline coatings on a substrate, comprising a spray head, a cleaning head and a handling system monitoring the spray head and the cleaning head relative to the substrate to be coated, the spray head being a first cold spray head, the first cold spray head depositing on the substrate at least one nanocrystalline powder, the cleaning head optimizing the surface being coated with the at least one layer of nanocrystalline powder.