Spray forming

About: Spray forming is a research topic. Over the lifetime, 1153 publications have been published within this topic receiving 12869 citations. The topic is also known as: spray casting & spray deposition.

Fundamentals of the Spray Forming Processes for Fabrication of Materials

Abstract: Spray forming is a complicated process controlled by many variables. In order to control the microstructure of the spray deposited preforms to obtain the optimum properties, it is important to thoroughly understand the fundamentals of the spray forming deposition processes, and the factors of the processing parameters. In this paper, the major processes and the influential factors concerning the spray forming process as well as the results of the theoretical and experimental analyses up to now in this field were briefly reviewed.

Ultrasonic spray coating system and spray-forming head thereof

Abstract: An ultrasonic spray coating system includes a piezoelectric transducer, a spray-forming head and a liquid supply applicator. The spray-forming head has an air-entrainment mechanism. The air-entrainment mechanism has an air-stream channel that is formed inside a main body and a bottom body of the spray-forming head for connection with a high-pressure air source, and an air vent formed in a bottom surface of the bottom body and communicates with the air-stream channel. A length of the air vent in a horizontal direction is greater than that of the air-stream channel. The liquid supply applicator has a discharge orifice, and a control component for controlling the size of the discharge orifice.

Recent INEL spray-forming developments

Abstract: Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing, oftentimes while substantially improving product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offersproperty improvements resulting from rapid solidification (eg. refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials using de Laval nozzles. Results from several spray-forming programs are presented to illustrate the range of capabilities of the approach as well as the technical and economic benefits. These programs involved the production of low-carbon steel strip and SiC particulate reinforced aluminum strip; recent advances in spray forming tooling using low-melting-point metals are also described.

A Comparative Study on Microstructure and Tensile Properties of Spray Formed and Ascast Al-28Si-5Cu-4Fe and Al-28Si-5Cu-4Mg Alloys

Abstract: In the present study, Al-28Si, Al-28Si-5Cu-4Fe and Al-28Si-5Cu-4Mg alloys were produced by spray forming and subsequently hot pressed for densification. The effect of alloy composition on the microstructure and mechanical behavior of spray-formed alloys were investigated. The microstructures consist of an equiaxed, nearly spheroidized grain morphology of α-Al matrix. The spray formed alloys exhibited sharply decreased segregation and increased metastable solid solubility and greater volume fraction of Si particles and intermetallic phases. Spray formed Al-28Si-5Cu-4Fe alloy contains Al 2 Cu, Al 5 FeSi along with Si. On the other hand, Al-28Si-5Cu-4Mg alloy showed Al 2 Cu, Al 48 Si 29 Mg 18 and Si. Hot pressing lead to a significant reduction of porosity and partial recrystallization of spray formed alloys. The room temperature tensile tests of spray formed hot pressed alloys showed significant increase in ultimate tensile strength compared to as cast alloys. Spray formed hot pressed Al-28Si-5Cu-4Fe alloy exhibited superior ultimate tensile strength and significant increase in elongation to fracture. This may be attributed to the presence of homogeneous distribution of fine Si particles, high content of short needle-like β-Al 5 FeSi intermetallic and precipitation strengthening phases.

Microstructure characteristics of spray-formed high speed steel and its evolution during subsequent hot deformation

Abstract: The microstructural evolution of spray-formed high speed steel during hot deformation was investigated as well as the effects of spray forming parameters on the porosity formation. Four distinct zones are identified in the as-deposited material, and interstitial porosity is present in the bottom and peripheral zones, while gas-related porosity is mainly found in the central zone. It can keep the porosity at a minimum value by using the optimum parameters, e.g., the average porosity of central zone is 3.7% for a superheat of 170 °C and a gas-to-metal flow rate of 0.7. During hot deformation at 1150 °C, the amount of porosity can be obviously decreased by increasing the height reduction which also plays a key role in breaking up eutectic carbides. The critical height reduction for the breakdown of the eutectic carbides is 50%, the dominant mechanism being mechanical fragmentation.