DAMPING CAPACITY AND CREEP RESISTANCE OF SPRAY DEPOSITED HIGH-SILICONALLOY ZA27

High Al zinc-based alloys are widely used in industry for their good a mbient temperature mechanical properties and damping capacity. With th e rise of service temperature its damping property increases but mecha nical property decreases greatly. Here two ways-alloying and spray dep osition technique were adopted to improve the service temperature limi tation of the alloy ZA27 in an effort to develop a new functional mate rial with high damping capacity and good elevated temperature mechanic al property. The effects of addition of 5 wt pet of Si on the damping behaviour and elevated temperature creep resistance of alloy ZA27 were investigated. The damping capacity, as well as the relative dynamic m odulus, was measured at frequency of 1,4 Hz over the 303 to 573 K. No peak phenomenon was observed for the specimens tested in the temperatu re range of interest. Experimental results indicated that the damping capacity of the deposited material was 2.8 times higher than that of t he cast one at 305 K. The ball hardness values were used to evaluate t he creep property and the creep activation energy of the deposited mat erial is 3.9 similar to 5.7 kJ per mol higher than that of the as-cast one. The creep rate formulation was also derived. Finally, the operat ive damping and creep mechanisms were discussed in the light of the da ta obtained from its characterization of microstructure, damping capac ity and creep resistance.