Spark plasma sintering the spark-erosion powders of functional alloys

Abstract

Various shape memory alloys (Ti-Ni-Hf, Ni-Al and Cu-Al-Ni) were elaborated by spark plasma sintering method from the micron, submicron and nano- sized particles prepared by spark-erosion method in cryogenic liquid from preliminary melted master alloys. These alloys are being developed as one of the alternatives for the intermediate temperature applications (100-900oC). Spark plasma sintering method is express method, which provides lower temperature and shorter holding time of sintering. It makes possible to sinter materials from the pre-alloyed powders and eliminate the intensive grains growth and precipitating processes influencing the mechanical and functional properties of functional materials. The effects of processing parameters on the martensitic transformation and microstructure of the sintered compacts were investigated using XRD and SEM study. Temperatures of sintering were chosen according to the assessed data of the decomposition, oxidation and others processes carrying out in material. Although the precipitating processes were usually not completely depressed, the intensive grain growth was also not found in most cases. Most of the microstructure peculiarities of as processed powder were inherited by the sintered material. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20798