scholarly journals Performance characteristics of polylactide-talc composites

2020 ◽  
Vol 3 (2) ◽  
pp. 163-168
Author(s):  
D.S. Katruk ◽  
◽  
Kh.V. Kysil ◽  
B.I. Kulish ◽  
A.S. Masyuk ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Diffusion Process ◽  
Heat Resistance ◽  
Thermophysical Properties ◽  
Surface Hardness ◽  
Additional Heat ◽  
Thermomechanical Characteristics ◽  
Heat Treated

The influence of the filler – talc, its content, additional heat treatment and temperature on the physical-mechanical and thermophysical properties of polylactide materials, in particular on the surface hardness, heat resistance according to Vick and thermomechanical characteristics has been studied. The influence of filler and temperature on the resistance of polylactide materials to the action of the aqueous medium is revealed. The diffusion coefficient of water in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by filled and heat- treated materials based on polylactide is slower and requires more activation energy of the process.

scholarly journals Resistance of Polylactide Materials to Water Mediums of the Various Natures

2021 ◽  
Vol 15 (2) ◽  
pp. 191-197
Author(s):  
Volodymyr Levytskyi ◽  
◽  
Diana Katruk ◽  
Andriy Masyuk ◽  
Khrystyna Kysil ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Water Absorption ◽  
Alkaline Media ◽  
Process Stability ◽  
Additional Heat ◽  
Heat Treated ◽  
Acidic And Alkaline Media ◽  
Water Diffusion Coefficient

The influence of talc filler, its content, as well as an additional heat treatment and temperature on the regularities of polylactide materials water-absorption has been researched. Based on the obtained data, the water diffusion coefficient in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by the filled and heat-treated materials based on polylactide proceeds slower and requires more activation energy of the process. Stability of the developed polylactide materials to acidic and alkaline media has been determined, in particular, it was found that the destruction of polylactide samples occurs faster in an alkaline medium than in an acidic one

High Indentation Resistance of Aluminum Borate Based Glass-Ceramics

2013 ◽  
Vol 545 ◽  
pp. 3-7
Author(s):  
Pat Sooksaen ◽  
Pisud Prasertcharoensuk ◽  
Jiraporn Damnernsawat ◽  
Nimit Pattamawitayanimit
Keyword(s):  
Heat Treatment ◽  
Glass Melting ◽  
Isothermal Holding ◽  
Surface Hardness ◽  
Glass Ceramics ◽  
Isothermal Heat Treatment ◽  
Aluminum Borate ◽  
Holding Period ◽  
Heating And Cooling ◽  
Heat Treated

This study investigated the bulk crystallization of 54B2O3-19SiO2-17Al2O3-5BaO-5MgO (mol%) glass. Melting was carried out at 1500°C for 1 h using a bottom-load electric furnace. The glass melt was cast into a block and annealed at 500°C for 2 h. Isothermal heat treatment was carried out at 1100°C for 2, 4, 8, 16, 32 h to form bulk crystallized glass-ceramics using a heating and cooling rate of 5°C/min. Phases present in the glass-ceramic samples were studied by x-ray diffraction. Crystalline Al4B2O9 and Al18B4O33 were the main phases and the phase stability depended on the isothermal time. Microstructures were observed by a scanning electron microscope. The size of aluminum borate whiskers/rods tend to increase with longer isothermal holding period. The whisker/ rod-like crystals uniformly oriented throughout the microstructure in all heat treated samples. This led to interlocking microstructure and hence an increase in hardness and fracture toughness. Glass-ceramics synthesized at longer heat treatment times resulted in an increase in the surface hardness and shorter path length at the corner of the diamond pyramid-shaped indenter. Glass-ceramics synthesized in this study can be applied as high temperature resistant machinable materials because their microstructures can resist micro-cracking upon indentation.

THE EFFECT OF HEAT TREATMENT OF MILK UPON THE HYDROLYZABILITY OF LACTOSE BY THE ENZYME LACTASE1

1970 ◽  
Vol 33 (9) ◽  
pp. 377-379 ◽  
Author(s):  
W. L. Wendorff ◽  
C. H. Amundson ◽  
N. F. Olson
Keyword(s):  
Heat Treatment ◽  
Salt Solution ◽  
Milk Protein ◽  
Lactose Hydrolysis ◽  
Additional Heat ◽  
Total Solids ◽  
Heat Treated ◽  
Dry Milk ◽  
Double Heat Treatment ◽  
Spray Dried

Heat treated, condensed skimmilk and nonfat dry milk (NDM) were treated with lactase enzyme obtained from Saccharomyces fragilis. The effect of heat treatment on lactose hydrolysis was determined. Forewarming treatments of 62.8, 68.3, 73.9, 79.5, and 85.0 C resulted in 17, 17, 100, 59, and 156 g, respectively, of lactose hydrolyzed. Concentrates with forewarming treatments of 62.8, 73.9, and 85.0 C for 30 min were given additional heat treatments of 62.8, 73.9, or 85.0 C for 20 min. Activity was lower in all concentrates given the double heat treatment, except those heated at 85.0 C for 20 min after forewarming at 62.8 and 73.9 C. These showed a substantial increase in lactose hydrolysis. Portions of each concentrate, spray dried and reconstituted to 30% total solids, exhibited the same effect on lactose hydrolysis as the original concentrates. Additional studies were conducted with whey and a 5% lactose plus milk salt solution. Results indicated that heating lactose in the presence of milk protein had a great effect on lactose hydrolysis.

Mechanical Properties of Nano-Crystalline Glaze for Wall Tiles Prepared by Controlling TiO2 Nucleating Agents

2020 ◽  
Vol 12 (4) ◽  
pp. 502-509 ◽  
Author(s):  
Yoorim Rho ◽  
Seunggu Kang ◽  
Jinho Kim ◽  
Kangduk Kim
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Crystallization Temperature ◽  
Surface Hardness ◽  
High Hardness ◽  
Nucleating Agent ◽  
Nano Crystalline ◽  
Heat Treated ◽  
Opaque Glaze ◽  
Degree Of Crystallization

In this paper, TiO2 is substituted as a nucleating agent in opaque glaze to produce nano-crystalline glaze with high hardness. The crystallization mechanism of glaze was calculated by non-isothermal thermal analysis by Differential Thermal Analysis (DTA), and the glaze was heat treated at the crystallization temperature (Tp). In the case of glaze (88G20T), in which TiO2 was substituted by 20 wt% showed surface crystallization behaviors because the Avrami constant (n) was 1.18 and the activation energy (E) values were 747.0 kJ/mol at the crystallization temperature (Tp2). The microstructure of the glazes without heat-treatment showed that phase separation transferred from spinodal to nucleation-growth as TiO2 substitution increased. The size of droplets was nano-sized, below 100 nm. The glazes heated at the crystallization temperature (Tp) and crystal size of several hundred nm to several μm was observed. The surface hardness of the crystalline glaze showed a high hardness of 6.74 GPa and the degree of crystallization was 47.5% at 80G20T after heat treatment at Tp2 (1207 °C).

scholarly journals Взаимодействие атомов сурьмы с микропорами в кремнии

2018 ◽  
Vol 60 (1) ◽  
pp. 22
Author(s):  
В.Б. Оджаев ◽  
А.Н. Петлицкий ◽  
В.И. Плебанович ◽  
П.К. Садовский ◽  
М.И. Тарасик ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Process ◽  
Electrical Activity ◽  
Subsequent Heat Treatment ◽  
Capture Process ◽  
Treatment Processes

AbstractThe interaction between Sb atoms and micropores of a getter layer in silicon is studied. The getter layer was obtained via implantation of Sb^+ ions into silicon and subsequent heat treatment processes. The antimony atoms located in the vicinity of micropores are captured by micropores during gettering annealing and lose its electrical activity. The activation energy of capture process to the pores for antimony is lower than that of antimony diffusion in silicon deformation fields around microvoids on the diffusion process.

scholarly journals Effect of Microstructure on Thermophysical Properties of Heat-Treated Duplex Steel

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6043
Author(s):  
Piotr Koniorczyk ◽  
Judyta Sienkiewicz ◽  
Janusz Zmywaczyk ◽  
Andrzej Dębski ◽  
Mateusz Zieliński ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermophysical Properties ◽  
Room Temperature ◽  
Laser Flash ◽  
Micro Hardness ◽  
Scanning Calorimetry ◽  
Air Atmosphere ◽  
Steel Bar ◽  
Heat Treated ◽  
Duplex Steel

The purpose of this study is to investigate the effect of heat treatments and resulting changes in microstructure on the thermophysical properties of commercial 1.4462 duplex stainless steel. Three types of heat treatment and a raw sample were used. In the first heat treatment, a duplex steel bar was annealed in an air atmosphere furnace for one hour at 1200 °C and then quickly cooled in water (1200 °C + water). The second heat treatment was the same as the first, but afterwards, the bar was annealed in an air atmosphere furnace for 4 h at 800 °C and then slowly cooled down in the furnace to room temperature (1200 °C + water + 800 °C). In the third heat treatment, the duplex steel bar was annealed in the furnace in an air atmosphere for one hour at 900 °C and then slowly cooled in the furnace to room temperature (900 °C). As a result, the weight percentages of ferrite and austenite in the samples achieved the following ratios: 75:25, 65:35 and 44:56. Light microscope examinations (LM), scanning electron microscopy (SEM), Vickers micro-hardness measurements and thermophysical studies using a laser flash apparatus (LFA), differential scanning calorimetry (DSC) and push-rod dilatometry (DIL) were performed to reveal the microstructure and changes in thermophysical properties including thermal diffusivity, thermal conductivity, thermal expansion and specific heat. Along with presenting these data, the paper, in brief, presents the applied investigation procedures.

The differentiation of curd made from heated and raw milk

1973 ◽  
Vol 40 (1) ◽  
pp. 1-6 ◽  
Author(s):  
K. C. Guha ◽  
B. R. Roy
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Microbial Growth ◽  
Whey Proteins ◽  
Raw Milk ◽  
First Order ◽  
Heat Treated ◽  
Native Whey ◽  
Indian Law ◽  
Kinetics Of

SummarySince Indian law requires curds to be made from heat-treated milk, a means for distinguishing between curds made from raw and from heat-treated milks was sought. Curds contain whey proteins that are partly or completely denatured by heat treatment; the kinetics of the reaction are first order. The concentrations of native whey proteins in raw and heat-treated milks and in curds made from those milks were measured. No difference was found between the concentrations in heattreated milk and in the curds made from it, so that identical values were obtained for the half-life on heating and for the activation energy of denaturation. The acidity and microbial growth occurring during the production of curd did not affect the whey proteins. On electrophoresis, curd from raw milk gave a few whey protein bands, but curd from milk boiled for 10 min gave none, showing complete denaturation of the whey proteins.

Quality Control of Heat-Treated Surface of 20CrMo Steel Transmission Countershaft

2011 ◽  
Vol 199-200 ◽  
pp. 1528-1531
Author(s):  
Hong Mei Wang ◽  
Xiao Juan Wang ◽  
Xiao Chun Ma
Keyword(s):  
Heat Treatment ◽  
Process Parameters ◽  
Surface Hardness ◽  
Reliable Operation ◽  
Soft Zone ◽  
Automotive Transmission ◽  
Heat Treated ◽  
Effective Depth ◽  
Hardened Surface

After heat treatment, the surface hardness and effective depth of hardened layers of automotive transmission countershaft, determines the quality of the part itself as well as the normal and reliable operation of the transmission assembly. The paper analyzes the specific reasons for such problems as soft zone on the hardened surface of transmission countershaft when proceeding with carbonitriding in the controlled atmosphere furnace, a multi-purpose furnace. And with process parameters adjusted, the process parameters of heat treatment are corrected that the soft zone has been eliminated and the quality of parts has been effectively controlled.

scholarly journals Effect of cobalt oxide on the sintering and grain growth of Al2O3-YAG composite nanopowder

2010 ◽  
Vol 42 (3) ◽  
pp. 321-328 ◽  
Author(s):  
S.A. Hassanzadeh-Tabrizi ◽  
E. Taheri-Nassaj
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Cobalt Oxide ◽  
Grain Growth ◽  
Average Particle Size ◽  
Average Particle ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Heat Treated ◽  
Cobalt Oxide Doping

In the present study, the effect of cobalt oxide on the densification of Al2O3-YAG composite nanopowder was investigated. An amorphous nanopowder was synthesized and crystallized to Al2O3-YAG after heat-treatment via a solid-state reaction. The average particle size of heat-treated powder at 800?C was about 80 nm. Cobalt oxide improved the sintering rate of Al2O3-YAG composite nanopowders and promoted grain boundary mobility. Cobalt oxide doping increased the ratio of densification/grain growth rate. The activation energy for grain growth decreased from 590 to 485 kJ/mol by adding cobalt oxide to the composite nanopowder.

scholarly journals Effect of Laser Heat-Treatment and Laser Nitriding on the Microstructural Evolutions and Wear Behaviors of AISI P21 Mold Steel

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1487
Author(s):  
Won-Sang Shin ◽  
Hyun Jong Yoo ◽  
Jeoung Han Kim ◽  
Jiyeon Choi ◽  
Eun-Joon Chun ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Base Metal ◽  
Surface Hardening ◽  
Surface Hardness ◽  
Laser Heat Treatment ◽  
Laser Nitriding ◽  
Laser Heat ◽  
Heat Treated ◽  
Pin On Disk

Laser heat-treatment and laser nitriding were conducted on an AISI P21 mold steel using a high-power diode laser with laser energy densities of 90 and 1125 J/mm2, respectively. No change in surface hardness was observed after laser heat-treatment. In contrast, a relatively larger surface hardness was measured after laser nitriding (i.e., 536 HV) compared with that of the base metal (i.e., 409 HV). The TEM and electron energy loss spectroscopy (EELS) analyses revealed that laser nitriding induced to develop AlN precipitates up to a depth of 15 μm from the surface, resulting in surface hardening. The laser-nitrided P21 exhibited a superior wear resistance compared with that of the base metal and laser heat-treated P21 in the pin-on-disk tribotests. After 100 m of a sliding distance of the pin-on-disk test, the total wear loss of the base metal was measured to be 0.74 mm3, and it decreased to 0.60 mm3 for the laser-nitrided P21. The base metal and laser heat-treated P21 showed similar wear behaviors. The larger wear resistance of the laser-nitrided P21 was attributed to the AlN precipitate-induced surface hardening.

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