Авіаційно-космічна техніка та технологія (Dec 2018)
IMPLEMENTATION OF THE METHODS OF POWDER METALLURGY INTO PROCESSES OF SERIAL PRODUCTION OF THE GTE HEAT RESISTANT TITANIUM BLADES
Abstract
The questions associated with improvement of efficiency of aircrafts and engines manufacture are considered. In the given context when new aircraft engines are developed, the growth of a share of easy materials such as heat resistant titanium alloys is observed. This is explained by successful complex of physical-mechanical properties, where the mechanical properties to weight ratio is the principal ones. It is noticed, that serial production’s technology of such alloys has high power inputs (double vacuum arc re-melting) and requires a strict composition control of alloying elements, impurities and uniformity of their distribution in the ingot structure. Significant difficulties are attributed to multi-stage deformation processing of large-tonnage ingots from multi-doped titanium alloys, such as ВТ8 alloy. This processing is needed in the operation chain for obtaining the small-sized rod-shaped half-products for production of GTE series blades billets. For elimination the shortcomings of serial technology, such as a large number of operations, the application of the powder metallurgy methods (PM) with technical-economical advantages is offered. The analysis of research results of composition, structure and physical-mechanical properties of an experimental alloy as ВТ8 shows that it is possible to gain the half-finished products of multi-doped titanium alloys with controlled chemical composition after sintering by methods of powder metallurgy. Mechanical properties of such alloy are approximated to serial alloy ВТ8 and thus it is permitted to use the experimental alloy as ВТ8 as constructional material for components which are not subjected to impact and cyclic loadings at the work temperatures like for serial alloy prototype. Received alloy is differed by presence of residual porosity and structure typical for two-phase sintered titanium alloys. For reducing of experimental alloy as-ВТ8 to requirements of the normative documentation (ND) for serial alloy ВТ8 and further implementation, investigation of influence of deformation processing on its structure and mechanical properties was carried out.
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