Papers by Author: Franciszek Binczyk

Abstract: mpact of heat treatment on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy MAR-247 post production rejects. Castings made in the processes of modification and filtration when pouring into moulds were subject to solubilization (1185°C/2 h) with subsequent ageing (870°C/20 h). It has been found on the basis of performed tests that in conditions of high-temperature creep at temperature 980°C with stress σ = 150 MPa the resistance of specimens of coarse-grain structure was significantly higher when compared to fine-grain material. The conditions of initiation and propagation of cracks in these specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. Moreover, it has been proven that creep resistance of heat treated MAR-247 superalloy significantly improves when compared to its condition after the process of modification only. Macrostructural changes in the MAR-247 superalloy that determine the increase of superalloy creep resistance after solubilization and ageing, as observed in the tests, were also examined.

Abstract: mpact of complex modification and filtration during pouring into moulds on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy IN-713C post production rejects. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. It has been demonstrated that in conditions of high-temperature creep at temperature 980°C with stress σ =150 MPa creep resistance of the IN-713C superalloy increases significantly with the increase of macrograin size. Creep resistance of specimens made of coarse grain material was significantly higher than the resistance of fine grain material.

Abstract: The paper presents the results of ATD thermal analysis of feed ingots (master heat) and castings made from IN-713C, MAR-247 and MAR-509 superalloys. Metallurgical quality assessment was made based on the analysis of dT/dt curve in rage from T_eut to T_sol. Furthermore, impurities (oxides of Al, Zr, Hf, Cr etc.) have been identified inside the shrinkage cavities of feed ingots and castings. Significant similarities has been observed between impurities found in ingots, ATD test samples and finished castings. It has been demonstrated that ATD analysis of samples taken from different parts of feed ingot can be effective method of metallurgical quality assessment for these ingots.

Abstract: The paper presents the results of the investigations of the solidification process of magnesium alloys containing 5 and 10 wt.% Al, the additions of Zn, Cu, Ni, and of an AlTiB master alloy. The plotted DTA (derivative thermal analysis) curves were used for the determination of solidification parameters Tliq, Teut and Tsol. Knowledge of these parameters is very important in determination of alloy pouring temperature and maximum casting operating temperature. On samples taken from the area of temperature measurements, the chemical composition and microstructure were determined. The density and hardness HB were measured as well. Applying the method of multiple regression analysis at the significance level α = 0.1, the intensity and direction of the effect of alloying elements on the solidification parameters, density and hardness HB of castings were evaluated.