Corrosion, wear and mechanical properties of pulse-electrodeposited alloys. Final report, September 1983-November 1986

Technical Report · Sun Mar 01 04:00:00 EST 1987

OSTI ID:6511925

Weil, R; Kim, W

The objective of this investigation was the use of pulse plating to improve the properties of electrodeposits and to develop new materials. It was necessary to design and build a minitensile device capable of measuring elastic and plastic properties of thin foils over a large range of strain rates and which used a specimen with the width and gage length scaled to the thickness. A cell for determining hydrogen permeation through electrodeposits was also built. The previously reported reduction of the internal stress in nickel-molybdenum deposits was investigated further as was that in nickel. An observed compressive stress which developed each time that the current was turned on and then changed to tensile was explained in terms of hydrogen expanding the surface layer. Hydrogen was also thought to be responsible for a decreasing stress with increasing pulse frequency when nickel was plated on palladium substrates. The reduction of Mo by hydrogen also during the time the pulsed current was off was the probable cause of a higher alloy content of Ni-Mo deposits and lower stress. The mechanical properties of Ni-Mo deposits were determined. The reason for the high ductility exhibited by composites consisting of alternate layers of ordered and disordered beta brass obtained by pulse plating was found to be due to a strain-induced martensitic transformation. Apparently, martensite strengthened the region where necking started and inhibited its leading to fracture. Grain-size refinement resulting from the periodic imposition of anodic pulses lead to a three-fold strength increase in nickel deposits as well as a decrease in their coefficients of friction.

• Research Organization: Stevens Inst. of Tech., Hoboken, NJ (USA)
• OSTI ID: 6511925
• Report Number(s): AD-A-178596/3/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
BRASS
CARBON ADDITIONS
CHEMICAL REACTIONS
COATINGS
COPPER ALLOYS
COPPER BASE ALLOYS
CORROSION
CRYSTAL STRUCTURE
DEPOSITION
DIMENSIONS
DUCTILITY
ELECTRODEPOSITED COATINGS
ELECTRODEPOSITION
ELECTROLYSIS
ELEMENTS
FRICTION
GRAIN SIZE
HYDRIDATION
HYDROGEN
IRON ALLOYS
LAYERS
LENGTH
LYSIS
MARTENSITE
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALLURGY
METALS
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL
NICKEL ALLOYS
NONMETALS
PALLADIUM
PERMEABILITY
PHYSICAL METALLURGY
PLATING
PLATINUM METALS
PULSES
SIZE
STRAIN RATE
STRESSES
SUBSTRATES
SURFACE COATING
SURFACES
TENSILE PROPERTIES
THICKNESS
TRANSITION ELEMENTS
WEAR
ZINC ALLOYS