Wyniki wyszukiwania - BazTech

1

ATD and DSC Analysis of IN-713C and ZhS6U-VI Superalloys

Binczyk F., Cwajna J., Gradoń P.

Archives of Foundry Engineering

|

2017

|

Vol. 17, iss. 1

13--16

EN

Paper presents the results of ATD and DSC analysis of two superalloys used in casting of aircraft engine parts. The main aim of the research was to obtain the solidification parameters, especially Tsol and Tliq, knowledge of which is important for proper selection of casting and heat treatment parameters. Assessment of the metallurgical quality (presence of impurities) of the feed ingots is also a very important step in production of castings. It was found that some of the feed ingots delivered by the superalloy producers are contaminated by oxides located in shrinkage defects. The ATD analysis allows for quite precise interpretation of first stages of solidification at which solid phases with low values of latent heat of solidification are formed from the liquid. Using DSC analysis it is possible to measure precisely the heat values accompanying the phase changes during cooling and heating which, with knowledge of phase composition, permits to calculate the enthalpy of formation of specific phases like γ or γ′.

2

Application of evolutionary algorithms to optimize the model parameters of casting cooling process

Kluska-Nawarecka S., Górny Z., Smolarek-Grzyb A.

Archives of Foundry Engineering

|

2010

|

Vol. 10, iss. 4

89--92

EN

One of the most commonly used methods of numerical simulation is the finite element method (FEM). Its popularity is reflected in the number of tools supporting the preparation of simulation models. However, despite its usefulness, FEM is often very troublesome in use; the problem is the selection of the finite element mesh or shape function. In addition, MES assumes a complete knowledge of the simulated process and of the parameters describing the investigated phenomena, including model geometry, boundary conditions, physical parameters, and mathematical model describing these phenomena. A comparison of the data obtained from physical experiments and simulations indicates an inaccuracy, which may result from the incorrectly chosen shape of element or geometry of the grid. The application of computational intelligence methods, combined with knowledge of the manufacturing technology of metal products, should allow an efficient selection of parameters of the mathematical models and, as a consequence, more precise control of the process of the casting solidification and cooling to ensure the required quality. The designed system has been integrated with the existing simulation environment, which will significantly facilitate the preparation and implementation of calculations of this type. Moreover, the use of a distributed model will significantly reduce the time complexity of calculations, requiring multiple repetition of complex simulations to estimate the quality of the different sets of parameters.

3

The problems connected with the solidification parameters estimation

Bartocha D.

Archives of Foundry Engineering

|

2008

|

Vol. 8, iss. 1

198-208

EN

In the article results of thermo-physical properties estimation are presented. Thermo-physical properties estimation was carried out with trial-and-error method on the base of the model computer simulations results. In the first step the computer simulations of self-cooling and heating processes for different thermo-physical properties of specimen alloy and for proposed two testers geometry was carried out. thermo-physical properties of specimen alloy were artifical, assumed by author. The results of simulation in the form of self-cooling and heating curves were used in the second step of work. In the second step the computer simulations to thermo-physical properties estimation by trial-and-error method was carried out. In these simulations only thermo-physical properties of specimen alloy were estimated, thermophysical properties of others materials and boundary conditions were exactly the same as in model simulations. finally thermo-physical properties assumed in first step were compared to estimated in second step.