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.

Effect of processing parameters on physical properties of spray formed and stir cast Al–2Mg–TiO2 composites

Abstract: In the present study, a modified spray forming set-up has been used to prepare Al–2Mg–TiO2 composites. Up to 6 and 11% by weight of the rutile particles have been successfully incorporated in Al–2Mg matrix using the modified spray forming technique. The density measurement reveals that the optimum nozzle-to-substrate distance is 30 cm and the optimum speed of rotation of the substrate is 8 rpm. The electrical resistivity measurement shows that resistivities of composites are marginally greater than the base alloy. The cold rolled alloy shows a wider hump in the resistivity variation, due to the recrystallization of the matrix. Similar observations are made in case of both stir cast and spray formed Al–2Mg–TiO2 composites. The kinetics of recrystallization of composites is faster than the matrix alloy. This is evident from relatively small hump in resistivity variation with temperature of composites. The fast recrystallization kinetics in composites is due to the generation of dislocations owing to the thermal mismatch between the Al matrix and the rutile particles. In addition to the hump at lower temperature, resistivity measurement of Al–2Mg–TiO2 composites shows a peak at temperature between 350 and 400 °C. The peak is due to the formation of the TiAl3 phase at TiO2 particle–matrix interface. Thermal conductivity of spray formed Al–2Mg–TiO2 composite is greater than the base alloy.

Spray forming polymer membranes, coatings and films

Abstract: A method of forming a polymer film having controlled physical and chemical characteristics, wherein a plume of nebulized droplets of a polymer or polymer precursor is directed toward a substrate from a converging/diverging nozzle having a throat at which the polymer or a precursor thereof is introduced and an exit from which the nebulized droplets of the polymer or precursor thereof leave entrained in a carrier gas. Relative movement between the nozzle and the substrate is provided to form a polymer film. Physical and chemical characteristics can be controlled by varying the deposition parameters and the gas and liquid chemistries. Semipermeable membranes of polyphosphazene films are disclosed, as are a variety of other polymer systems, both porous and non-porous.

Atomizer for spray forming ring structures

Abstract: A method and spray forming system for effectively spraying the inner diameters of intricate objects and makes inner diameter spray forming practical for articles that have various and complicated inner geometries. The spray forming system can include at least one of a rotating mandrel and preform, and atomizer, which is fed with liquid metal, to form a spray. The atomizer is positioned with respect to inner walls of at least one of the rotating mandrel and preform to accurately and fully spray form an inner diameter of an article, even if the article has complicated and irregular inner surfaces.

Plasma Spray Deposition: A Need for Direct Process Control

Abstract: Plasma spray deposition has become a spray forming technique for making thin, free standing metal matrix composites (MMC). Successful application of plasma spray forming as a production process for producing such highly engineered materials will require process controls which can, in real time, monitor and control the deposition process. The plasma process has historically been controlled by monitoring and controlling input variables which in many cases do not indicate the state of the materials being processed Direct methods of measurement and process control are needed, including plasma jet temperature, plasma jet velocity, particle temperature, deposit temperature, deposit thickness, deposit density and deposit defect levels. Direct measurement requires the use of non-destructive and/or non-intrusive measurements to determine absolute or relative “process” levels. NDE techniques applied to the plasma process will create the basis for “intelligent process control” which integrates process models, input variable controls and direct measurements.