Dependence between structure of cast Al-Ni-La alloys and their chemical composition

The peculiarities of cast Al-Ni-La alloys structure formation depending on the content and ratio of the main components are analyzed in the work. It is shown, that so far the studied system has been considered mainly for the creation of amorphous materials. At the same time, Al-Ni and Al-La systems have phase diagrams that allow us to consider double and triple alloys of these systems to create promising creep-resistant alloys for casting. At the same time, the peculiarities of their structure formation in this context were not determined. Samples with different contents of nickel and lanthanum were prepared for research and analyzed how each of the elements, their number and ratio affect the formation of their structural-phase state. It is shown, that low nickel content of about 2 wt. % and lanthanum up to 5 wt. % eutectic is formed like thin almost monolithic intermetallic plates. As the number of components increases and, accordingly, the number of eutectics increases, the dispersion of its components increases. The analysis of the alloy structure dependence due to studied system on their chemical composition showed that, most likely, during the formation of the eutectic, Al11La3 particles, which may have the form of nanosized fibers, are formed first of all. It should be noted that at the eutectic content of lanthanum in the alloys no primary-formed Al11La3 particles were found. This may indicate that nickel shifts the eutectic concentration of lanthanum toward higher values. At the same time, at the hypoeutectic concentration of lanthanum and the hypereutectic concentration of nickel, some Al11La3 formations were outside the regions of the main eutectic with nickel aluminide. Such questions necessitate further studies of the aluminum angle of the triple state diagram of the Al-Ni-La system. Keywords: Al-Ni-La system, creep-resistant cast aluminum alloys, structure, eutectic.

Application of cold gas dynamic spraying as an additive technology for producing materials based on nickel aluminide and titanium aluminide

Metal additive manufacturing is widely studied for its unique advantages over traditional manufacturing processes. It is used to form complex components of Ti, Fe or Ni alloys. However, for non-ferrous alloys – aluminum, magnesium, copper – additive technologies are not used due to rapid melting during laser, electron beam and/or arc treatment. Cold spraying is widely used as an effective technology for applying high quality coatings in the mass production of metal and alloy products and/or metal matrix composite coatings. In addition, cold spraying is a serious and effective tool for the additive manufacturing of metals, and research in this area is currently becoming intense. During heat treatment of materials obtained by cold spraying, new chemical compounds are formed – both intermetallic compounds and hardening ceramic inclusions that increase the microhardness. However, as a result of a change in the structure during chemical transformations, a change in the geometry of the product and the formation of pores can be observed.

Optimization of laser cladding parameters of nickel-based metal powder for creation a heat-resistant coating

Optimization of laser deposition of nickel aluminide was carried out to obtain a single track of high quality. The structure of single tracks was investigated. Based on the data obtained, a multilayer structure was deposited and a study of the distribution of elements was carried out.

Obtaining of Composite Alloys Based on Nickel Aluminides with Rare Metals

The paper presents the research results on the production of doped composite materials by the method of out-of-furnace liquid-phase self-propagating high-temperature synthesis using oxides and mineral concentrates containing Zr and W as a charge. The positive experience of producing ingots of intermetallic alloys based on the Ni-Al system in one stage of the reduction process of joint metallothermy is shown. The use of Zr in the charge leads to grinding of microstructure of the ingots and the formation of intermetallic compounds containing Zr. The additional use of C, B2O3, and W in the charge results in the formation of complex borides and tungsten carbides in the ingots. Additional introduction of Cr2O3 into the charge is necessary for the formation of W carbides in the nickel aluminide matrix.