Factors influencing the tensile strength, hardness, and ductility of hydrogen-cycled palladium

A systematic study of the tensile strength, hardness, and ductility of palladium has been performed on foil specimens that have undergone hydrogen absorption and desorption under a variety of conditions. The experimental parameters under control in the various hydrogen treatments were: (i) the amount of hydrogen absorbed, (ii) the isotope of hydrogen (protium versus deuterium) absorbed, (iii) the number of hydrogen absorption/desorption cycles, and (iv) the hydrogen absorption/desorption temperature. In all instances hydrogen absorption/desorption cycling significantly alters the tensile strength, hardness, and ductility of well-annealed palladium. The results show that, in general, the strength and hardness of palladium increases as a result of hydrogen cycling while the ductility decreases. The extent of the respective increases and decreases has been found to differ depending on the parameter being varied. The most sensitive parameter was found to be the amount of hydrogen absorbed during cycling.