scholarly journals The Effect of Temperature on the Result of Complex Modification of IN-713C Superalloy Castings

2015 ◽  
Vol 15 (4) ◽  
pp. 13-16
Author(s):  
F. Binczyk ◽  
P. Gradoń ◽  
M. Mańka ◽  
R. Findziński

Abstract The paper presents the results of research on the determination of the effect of pouring temperature on the macrostructure of the castings subjected to complex (surface and volume) modification and double filtration. Tested castings were made of post-production scrap (gating system parts) of IN-713C superalloy. Tests included the evaluation of the number of grains per 1 mm2, mean grain surface area, shape factor and tensile strength. Casting temperature below 1470 °C positively influenced the modification effect. The grains were finer and the mechanical properties increased, especially for castings with thicker walls. On the other hand, manufacture of thin walled castings of high quality require pouring temperature above 1480 °C.

2012 ◽  
Vol 24 (6) ◽  
pp. 843 ◽  
Author(s):  
Daniel Żarski ◽  
Sławomir Krejszeff ◽  
Katarzyna Palińska ◽  
Katarzyna Targońska ◽  
Krzysztof Kupren ◽  
...  

The aim of this study was to investigate the process of the cortical reaction in eggs of pikeperch, Sander lucioperca (L.), as well as the application of microscopic assessment of this process in egg quality evaluation. The analysis was carried out with eggs obtained from 10 females by artificial reproduction, in which hormonal stimulation with hCG was applied. Subsequently, each sample of eggs (separately from each female fish) was analysed. The analysis included observation of the cortical reaction and the process of egg swelling, and determination of the effect of temperature (12, 14 and 16°C) and the presence of spermatozoa on the cortical reaction. The results indicate that the cortical reaction in pikeperch eggs is quite violent, resulting in visible deformation of eggs between 3 and 5 min after activation. No effect of temperature or the presence of spermatozoa on the cortical reaction was observed. A strong correlation was recorded for the percentage of egg deformations observed and embryo survival rate. The described method of determination of pikeperch egg quality (based on egg deformation rate between 3 and 5 min after activation) may be highly useful, both in scientific research (where high-quality eggs are required) and in hatchery practice.


2005 ◽  
Vol 127 (3) ◽  
pp. 679-684 ◽  
Author(s):  
S. Charles ◽  
O. Bonneau ◽  
J. Fre^ne

The characteristics of hydrostatic bearings can be influenced by the compensating device they use, for example, a thin-walled orifice (diaphragm). The flow through the orifice is given by a law where an ad hoc discharge coefficient appears, and, in order to guarantee the characteristics of the hydrostatic bearing, this coefficient must be calibrated. The aim of this work is to provide an accurate estimation of the discharge coefficient under specific conditions. Therefore an experimental bench was designed and a numerical model was carried out. The results obtained then by the experimental and theoretical approach were compared with the values given by the literature. Finally, the influence of the discharge coefficient on the behavior of a thrust bearing is examined.


Lipid / Fett ◽  
1989 ◽  
Vol 91 (5) ◽  
pp. 200-203
Author(s):  
H. E. Pretorius ◽  
L. M. Du Plessis
Keyword(s):  

1985 ◽  
Vol 30 (3) ◽  
pp. 155-158 ◽  
Author(s):  
Joaquim Casal ◽  
Antoni Lucas ◽  
Josep Arnaldos

2011 ◽  
Vol 176 ◽  
pp. 91-98
Author(s):  
Franciszek Binczyk

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.


2016 ◽  
Vol 16 (3) ◽  
pp. 83-88 ◽  
Author(s):  
B.V. Omidiji ◽  
R.H. Khan ◽  
M.S. Abolarin

Abstract The influence of the refractory coating which is a mixture of silica flour and kaolin on the surface roughness of the plate castings produced using evaporative patterns had been considered in this work. The kaolin was used as a binder and ratio method was employed to form basis for the factorial design of experiment which led to nine runs of experiments. Methyl alcohol at 99% concentration was used as the carrier for the transfer of the coating to the surface of the patterns. Pouring temperature was observed as a process parameter alongside the mix ratios of the coating. Attempts were made to characterize the refractory coating by using two methods; differential thermal analysis (DTA) and X-ray diffraction. Attempt was also made to characterize the casting material. Gating system design was done for the plate casting to determine the correct proportions of the gating parameters in order to construct the gating system properly to avoid turbulence during pouring of liquid metal. A digital profilometer was used to take the measurements of the surface roughness. It was observed that the mix ratio 90% silica flour-10% kaolin produced the lowest value of the surface roughness of the plate castings and had the lowest material loss in the DTA test. The pouring temperature of 650°C produced best casting.


2021 ◽  
Vol 18 (39) ◽  
pp. 14-32
Author(s):  
Hind Sadiq Al-WARD ◽  
Mouayed Qassssim AL-ABACHI ◽  
Mohammed Rifaat AHMED

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.


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