Jobs Button PSU Button        
PSU PSU ARL Logo PSU Logo

Materials Processing

Cold Spray (High Velocity Particle Consolidation (HVPC))
High Velocity Particle Consolidation (HVPC), also known as cold spray, is a low-temperature coating technology in which small particles (1-50 µm) are injected into a high velocity gas stream to form a dense coating upon impact with a substrate.  The compressed and moderately heated gas (up to ~500°C) is accelerated to supersonic velocity in a De-Laval nozzle. Feedstock powder is injected into the gas jet at the nozzle intake and then propelled onto the substrate. Plastic deformation of particles upon impact produces high strength bonds between the powder and the substrate. Coatings may be applied onto flat, round, or rotating substrates, and the spray pattern is manipulated by a robot arm. The advantages of cold spray technology include: no particle melting during spray, no phase transformations in the material, and no oxidation, nitriding, or decarburization.  Current programs in HVPC coatings involve both fundamental and applied coating studies for commercial and military use. Primary cold spray applications include corrosion resistance, wear resistance, and defect repair.

CS3
HVPC equipment mounted to inverted robot
Materials Processing
HVPC coating application on cylindrical/rotating part

Electron Beam-Physical Vapor Deposition (EB-PVD)
EB-PVD is a materials coatings technology whereby coating materials including metal, alloy, or ceramic are melted within a vacuum and then deposited on a component or part requiring the surface properties inherent in the coating. A strong mechanical vapor bond, uniform microstructure, and relatively high deposition rates make it an attractive and versatile coating process. Since it is performed in a vacuum, it is an environmentally friendly technology, suitable as a replacement for other coating processes in many applications. (See also Coating Technologies)


EB-PVD Animation (Click here to download MPG animation)

Spray Metal Forming
The Metals and Ceramic Processing Department conducts research in the development and processing of high performance aluminum alloys produced by the Spray Metal Forming Process. High Velocity Particle Consolidation (HVPC), also known as cold spray, is a low-temperature coating technology in which small particles (1-50 µm) are injected into a high velocity gas stream to form a dense coating upon impact with a substrate. The compressed and moderately heated gas (up to ~500°C) is accelerated to supersonic velocity in a De-Laval nozzle. Feedstock powder is injected into the gas jet at the nozzle intake and then propelled onto the substrate. Plastic deformation of particles upon impact produces high strength bonds between the powder and the substrate. Coatings may be applied onto flat, round, or rotating substrates, and the spray pattern is manipulated by a robot arm. The advantages of cold spray technology include: no particle melting during spray, no phase transformations in the material, and no oxidation, nitriding, or decarburization. Current programs in HVPC coatings involve both fundamental and applied coating studies for commercial and military use. Primary cold spray applications include corrosion resistance, wear resistance, and defect repair.

The three main areas of focus are high temperature aluminum alloys, ultra-high strength aluminum alloys, and hypereutectic aluminum-silicon alloys. The alloys are produced on a research scale plant. The plant is capable of producing billets, plates and tubes. The melt capacity is 50 kg (110 lbs) of aluminum alloy. Billets with diameters of 150 to 250 mm (6 to 10 inches) can be produced with lengths up to 400 mm (16 inches) depending on the billet diameter. Plates can be produced that are 150 mm (6 inches) wide by 300 mm (12 inches) long with thickness up to 20 mm (0.8 inches).  Tube sizes range from 75 mm to 230 mm (3 to 9 inches) inside diameter with wall thickness up to 25 mm (1 inch). A powder feeder may be used to inject particulate reinforcement into the gas stream near the point of atomization to form a metal matrix composite with uniform distribution of the injected particulate.

SMF Composite

Corrosion Testing
Corrosion testing at ARL covers a wide range of techniques including electrochemical testing (DC: potentiodynamic and cyclic polarization, AC: electrochemical impedance spectroscopy (EIS)), immersion testing, material compatibility (galvanic corrosion), and salt spray (pitting and crevice corrosion). Laboratory resources consist of potentiostats, high-impedance voltmeters, solution analytical equipment, alternate immersion chamber, and a Singleton Cyclic Corrosion Test Chamber. Standardized tests frequently employed are ASTM B117 Salt Spray, G71 Galvanic Corrosion, G44 Alternate Immersion, G85 Modified Salt Spray, G60 Cyclic Humidity, G5 Polarization Measurements, G150 Critical Pitting Temperature, GM9540P, and SAE J2334.
Adv Coating
Electrochemical Corrosion Test Cell
Salt Spray
Singleton Cyclic Corrosion Test Chamber
Penn State University is unique in that it is one of the few facilities that have Type I and Type II hot corrosion testing capabilities with controlled SO2 contents. The Dean Rig test apparatus will be used to evaluate various materials under Type I (900°C) and Type II hot corrosion (705°C).  The apparatus generally consists of a multi-temperature zone furnace, alumina tube, molten sodium sulfate salt, and an O2-0.1%SO2 gas mixture.  At one end of the furnace, the O2-0.1%SO2 carrier gas mixture is passed through a platinized honeycomb catalyst upstream from the crucible containing the sodium sulfate (contained in an alumina crucible) maintained at approximately 900°C (temperature above the sodium sulfate melting temperature of 884°C).  The salt sprayed test specimens are then positioned in an alumina crucible (705°C) downstream from the molten sodium sulfate.  Deans Rig
Schematic illustration of Deans Rig testing apparatus
The difference in temperature along the various zones of the furnace allows the vaporized sodium sulfate salt to condense onto the surface of the test specimens held at the lower temperature 705°C (Type II hot corrosion).  Sodium sulfate salt is added to an alumina boat at the start of the experiment in order to maintain the equilibrium amount of SO3 which stabilizes the activity of the sodium sulfate allowing an accelerated corrosion method of the test specimens.  The salt sprayed specimens are then placed in an alumina tray contained in the lower temperature zone (705°C) of the Dean Rig for evaluation under Type II hot corrosion conditions. 

Hydraulic Hot Pressing

Hydraulic Hot Press with vacuum and inert atmosphere capabilities is used for powder consolidation and laminated ceramics at high temperatures. The 100 ton press with 5 inch diameter ram is only limited by die material/design.  Current temperature maximum is 1900°C. Typical vacuum level is 10-4 torr during operation. Tape cast slurry mixing, casting, and lay-up can tailor ceramic composition throughout a consolidated – pressed part.
Hydraulic Hotpress
Hydraulic Hot Press
Hydraulic Hotpress Chamber