Accession Number : ADA267557


Title :   Transient Phenomena Following Precipitation and Re-Solution Anneals in a NiTi Alloy


Descriptive Note : Final rept.,


Corporate Author : ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET LABS


Personal Author(s) : Meisel, L V ; Cote, P J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267557.pdf


Report Date : May 1993


Pagination or Media Count : 22


Abstract : Transient phenomena following anneals in a near stoichiometric NiTi alloy are investigated by means of differential scanning calorimetry (DSC). Precipitation anneals (350 deg C) raise the temperature range of the martensite and R-transformation. Subsequent cycling through the transformation range (-40 deg to 100 deg C) produces small changes in the martensite DSC peaks and no observable change in the R-peak. Subsequent re-solution anneals (600 deg C) produce dramatic effects: Ms rises approximately 20 deg C above its value preceding the precipitation anneal and the martensite DSC peak is very sharp and symmetric, while the R-transformation peak is not observable. During ensuing cycling, the martensite peak returns to its original form and position after about 300 cycles, and the R-peak appears after 4 cycles and is essentially invariant to cycling. The transient data are consistent with a dislocation model.... Differential scanning calorimetry, Shape memory alloys, Martensitic transformation, Phase transformation


Descriptors :   *PHASE TRANSFORMATIONS , *NICKEL ALLOYS , *TITANIUM ALLOYS , TRANSIENTS , TEMPERATURE , ALLOYS , TRANSFORMATIONS , CALORIMETRY , MARTENSITE , PRECIPITATION , DISLOCATIONS , CYCLES , SHAPE , ANNEALING


Subject Categories : Properties of Metals and Alloys


Distribution Statement : APPROVED FOR PUBLIC RELEASE