CHARACTERIZATION OF PRIMARY MICROSTRUCTURE OF THIN-WALLED NI-BASED SUPERALLOY CASTING

摘要

The paper presents a detailed analysis of the temperature distribution during the investment casting process in a multi-layer shell mould- Adequate selection of the preheating and pouring temperature as well as the preheating time affects the quality of the castings and the price of its manufacturing. The obtained microstructure is characterized by the high volume fraction of the main strengthening phases, namely γ'. Heterogeneity of the cores, and thus the presence of borides, eutectic γ/γ' and Zr-rich phase can be reduced by heat treatment.