Changes in viscosity of processed creams during storage at 5 °C

1984 ◽  
Vol 51 (2) ◽  
pp. 299-305 ◽  
Author(s):  
Keith R. Langley
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Fat Content ◽  
Heat Treated ◽  
Rate Of Increase ◽  
Fat Volume

SummaryThe viscosity of heat treated creams increased with time (t). The rate (k) was dependent on homogenization pressure, fat content and heat treatment temperatures. Viscosity and its rate of increase could be related by the expressions:log η = log η0 + kt(where η0 is the viscosity at t = 0),log η0 = a1 + b1φ/d(where φ is the fat volume fraction, d is the globule diameter) andk = a2 + b2φ/d.Different values of a1b1a2 and b2 were found for homogenized and unhomogenized creams.

Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3077-3089
Author(s):  
Alexeis Sánchez ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
I. Mejía
Keyword(s):  
Heat Treatment ◽  
Abrasive Wear ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Wear Behaviour ◽  
White Iron ◽  
Heat Treated ◽  
Bulk Hardness ◽  
Abrasive Wear Behavior ◽  
Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

Effects of Heat Treatment on Microstructure and Properties of AZ91D Magnesium Alloy

2013 ◽  
Vol 575-576 ◽  
pp. 410-413
Author(s):  
Ming Wu ◽  
Fang Long ◽  
Hao Ran Geng ◽  
Fang Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Test ◽  
Artificial Aging ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Second Phase ◽  
Az91d Alloy ◽  
Az91d Magnesium Alloy ◽  
Heat Treated

The microstructure, hardness and corrosion resistance of AZ91D alloy were investigated under different solution treatments and artificial aging conditions.When ascast AZ91D alloy was heat treated at 415°C by solution treatmentfor 12 h and artificially aged at 200°C, the volume fraction of precipitates increased with the aging time up to 10 h.When ascast AZ91D alloy was treated at 430°C by solution treatment for 12 h and artificially aged at 200°C for 10h, the volume fraction of precipitates reached a peak value.The results of the corrosion test showed that a high corrosion resisting of the second phase precipitates was beneficial to improving the strength and hardness. Solution treatment at 445°C temperature for 12 h destroied the consecutiveness of β-Mg17Al12 phases.

A viscometric study of the flocculation of the components in stored homogenized ultra-heat-treated cream

1982 ◽  
Vol 49 (4) ◽  
pp. 655-664 ◽  
Author(s):  
Leslie W. Phipps
Keyword(s):  
Volume Fraction ◽  
Particle Interaction ◽  
Relative Viscosity ◽  
Storage Period ◽  
Fat Globules ◽  
Heat Treated ◽  
Seasonal Factors ◽  
Image Position ◽  
Viscometric Study ◽  
Fat Volume

SUMMARYThe apparent relative viscosity (ηr) of stored homogenized ultra-heat-treated ‘coffee’ cream increased with time (t) at a rate which was a function of mean fat globule diameter (d) and fat volume fraction (ø); the rate was also influenced by Na2CO3and Na citrate when present as stabilizing additives. Viscosity increases were attributed to the progressive flocculation of fat globules and to the strengthening of the structure formed by the gradual accretion of casein micelles on to globule surfaces and their points of contact (bridging). The expressionwheretis in days anddin μm, was found to hold over a 12-week storage period for a batch of creams (ø = 0·143) of differentdvalues prepared from the bulk cream containing carbonate and citrate stabilizers; η0is the relative viscosity att= 0 andkis a rate parameter. In the absence of stabilizers the parameterkassumed a smaller value and so appeared to be a function of chemical composition of the cream and of forces of particle interaction; seasonal factors were also suspected of influencingk. The effect of the fat volume fraction on storage behaviour was not fully resolved, but there was some evidence that the proportionality log ηrα1/ø½ was appropriate.

scholarly journals Stereological Evaluation of Precipitates within Ferrite Grains in Heat-Treated 1.25Cr0.5Mo Steel Previously Exposed to Service

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Rafael Fernández-Fuentes ◽  
Americo Scotti ◽  
Amado Cruz-Crespo ◽  
Roberto Silva González ◽  
Rafael Ariza Gonçalves ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Digital Images ◽  
Post Weld Heat Treatment ◽  
Aged Material ◽  
Term Operation ◽  
Heat Treated ◽  
Service Operation ◽  
Weld Heat

The objective of this work was to study the effect of the heat treatment and further operation aging on the stereological parameters (size, quantity and volume fraction) of precipitates within ferrite grains of a creep-resistant 1.25Cr0.5Mo steel after long-term operation. The heat treatment was similar to the treatment that is carried out in industrial steam pipelines after welding (post weld heat treatment - PWHT) during installation and/or repairing. The operation aging corresponds to a subsequent long in-service operation after repairing. To determine the stereological parameters, SEM digital images were taken from samples of this material after conditions of in-service-aged (after long-term operation), in-service-aged and heat-treated (simulating repairing) and in-service-aged, heat-treated and in-laboratory aged (simulating subsequent long-term operation after repairing). The results indicate that the changes in the stereological parameters of the precipitates within ferrite grains after PWHT is associated with the coarsening process of the within-ferrite-grain precipitates as well as stabilizing the microstructure, since the material aging after PWHT of an in-serviced aged material would not change the stereological parameters.

scholarly journals NEW TREATMENT ROUTE FOR CLOSED-DIE FORGINGS OF STEELS WITH 2.5% MANGANESE

2018 ◽  
Vol 24 (2) ◽  
pp. 119
Author(s):  
Dagmar Bublíková ◽  
Štěpán Jeníček ◽  
Michal Peković ◽  
Hana Jirková
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Volume Fraction ◽  
High Strength ◽  
Quenching Temperature ◽  
Treatment Processes ◽  
Martensitic Microstructure ◽  
Heat Treated ◽  
Forged Parts ◽  
New Treatment

<p>The requirements placed on closed-die-forged parts of advanced steels have been increasing recently. Such forgings demand an innovative approach to both design and heat treatment. It is important to obtain high strength and sufficient ductility in closed-die forgings. High strength, mostly associated with martensitic microstructure, is often to the detriment of ductility. Ductility can be improved by incorporating a certain volume fraction of retained austenite in the resulting microstructure. Among heat treatment processes capable of producing martensite and retained austenite, there is the Q&amp;P process (Quenching and Partitioning). This process is characterized by rapid cooling from the soaking temperature to the quenching temperature, which is between Ms and Mf, and subsequent reheating and holding at the partitioning temperature. Thus, strength levels of more than 2000 MPa combined with more than 10% elongation can be obtained. This experimental programme involved steels with 2.5% manganese. Forgings of these steels were heat treated using an innovative process in order to obtain an ultimate strength of more than 2000 MPa combined with sufficient elongation. Thanks to a higher manganese level, the Mf was depressed as low as 78°C, and therefore quenching was carried out not only in air but also in boiling water. Holding at the partitioning temperature of 180°C, when carbon migrates from super-saturated martensite to retained austenite, took place in a furnace. The effects of heat treatment parameters on the resulting mechanical properties and microstructure evolution in various locations of the forging were studied.</p>

Residual Stress Analysis of A362 Aluminum Alloy Gear Case Using Neutron Diffraction

2018 ◽  
Vol 941 ◽  
pp. 1288-1294 ◽  
Author(s):  
Dimitry Sediako ◽  
Joshua Stroh ◽  
Alexandra McDougall ◽  
Ermia Aghaie
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Neutron Diffraction ◽  
Stress Analysis ◽  
Volume Fraction ◽  
High Stress ◽  
Microstructural Characterization ◽  
Heat Treated ◽  
Material State ◽  
Residual Stress Analysis

Mercury Marine has used a new alloy, Mercalloy A362, for the manufacturing of a re-designed lower unit transmission gearcase. The enhanced strength of the alloy allowed for a substantial weight reduction in the new design. The purpose of this study was to examine and determine why cracking may develop in the gear casing during in service testing. Two types of material states, (i) as cast and (ii) heat treated were compared. Metallography and neutron diffraction analysis was carried out at locations identified as being areas of high stress by Magma software – which was performed in a separate study. Microstructural characterization at these locations revealed microstructural and the compositional differences. Differences in the porosity, eutectic phase, and volume fraction of the precipitates were observed at various locations of interest in each material state. The residual stress analysis was performed with application of neutron diffraction and revealed that the stresses in the as-cast component reached a maximum value of 120 MPa, which is below the yield strength of the alloy. The heat treatment applied to the castings reduced the stress by approximately 50 MPa. Based on the microstructure and neutron diffraction results, it is likely that performing a heat treatment process extends the lifetime of the component, however, it may not completely eliminate the cracking problem. Farther studies are currently nearing completion, targeting the mass production of the redesigned gearcase.

Effects of Impregnating and Heat Treatment on the Oxidation and Thermal Shock Properties of Pressureless Sintered SiC/Graphite Composites

2012 ◽  
Vol 724 ◽  
pp. 311-314
Author(s):  
Wan Li Yang ◽  
Zhong Qi Shi ◽  
Zhi Hao Jin ◽  
Guan Jun Qiao
Keyword(s):  
Heat Treatment ◽  
Thermal Shock ◽  
Oxidation Resistance ◽  
Vickers Hardness ◽  
Volume Fraction ◽  
Nitrogen Atmosphere ◽  
Silica Sol ◽  
X Ray Diffraction ◽  
Heat Treated ◽  
Before And After

SiC/0~20% graphite (volume fraction) composites were successfully fabricated by pressureless sintering at 1700 °C for 2 h in nitrogen atmosphere. The impregnating and heat treatment process for the samples with silica sol/phenolic impregnant was carried out at 1450 °C for 2 h in nitrogen atmosphere. The Vickers hardness, oxidation resistance and thermal shock property of the composites before and after treatment were tested, and the microstructure and phase composition were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results shown that the Vickers hardness of SiC/20% graphite was increased from 3.35 GPa to 4.90 GPa by heat treatment, and the oxidation resistance and thermal shock property of the heat treated samples were also improved significantly. The SEM and XRD results revealed that the formation of new SiC particles by the reaction of silica sol and phenolic was the main reason for the mechanical properties improvements.

scholarly journals Design and Optimization of Processing Conditions for a Recent Quenched and Partitioned Steel

2021 ◽  
Author(s):  
Eman Hassan El-Shenawy ◽  
Hoda Nasr El-Din Hedia ◽  
Mai Mohamed Kama-El-Din ◽  
Hoda Refaiy Badwy
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Testing Machine ◽  
High Strength ◽  
Processing Conditions ◽  
Critical Temperatures ◽  
Tensile Testing Machine ◽  
Heat Treated

Q&P steels as a "Third Generation" of (AHSS) exhibit excellent tensile properties, which enable producing lightweight sections for the automotive industry and at the same time keep safety requirements. This research aims to predict the proper processing conditions for developing ultra-high-strength Q&P steel with a novel chemical composition of 0.37 C-3.65 Mn- 0.65Si- 0.87 Al- 1.5 Ni- 0.05P, wt. %. To design and optimize proper heat treatment conditions, the phase diagram, CCT curve, and critical temperatures of these alloys were first implemented using THERMO-CALC and JMATE PRO software and Gleeble 3500 machine. The heat treatment process included full austenitization, then quenching at 120°C followed by partitioning at 450°C for different times. The tensile properties, microstructure, and retained austenite volume fraction of heat-treated steel was studied at room temperature by tensile testing machine, optical microscope, and XRD. The finding summarized that partitioning of this steel for 100 s during processing had developed Q&P steel with ultra-high-strength of 1104 MPa with maximum total elongation and strength elongation balance 8.1 % and 8932 MPa %, respectively. The optical micrograph showed that heat-treated specimens at different partitioning times have had a microstructure of tempered martensite, carbide free bainite, and retained austenite. Besides, the retained austenite volume fraction has decreased with increasing partitioning time, which may be due to carbide precipitation during partitioning.

scholarly journals Chemical and Sensory Parameters of Heat-treated Vacuum-packaged Broiler and Hen Fillet Products

2012 ◽  
Vol 27 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Kristine Ramane ◽  
Envija Strautniece ◽  
Ruta Galoburda
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Protein Content ◽  
Meat Products ◽  
Fat Content ◽  
Sensory Properties ◽  
Poultry Meat ◽  
Heat Treated ◽  
Sensory Parameters ◽  
And Storage

Chemical and Sensory Parameters of Heat-treated Vacuum-packaged Broiler and Hen Fillet Products The heat treatment of vacuum-packaged products - Sous vide processing method - that offers convenience and storage stability, combined with poultry meat marinating was used in the current study. The aim of this research was to evaluate the effect of a fruit-vegetable additive on chemical and sensory parameters of heat-treated vacuum-packaged poultry meat products made from broiler or hen fillets. The skinless fillets and other ingredients were packaged in polyamide/polyethylene (PA/PE) pouches, vacuum sealed, marinated, heat treated, and chilled rapidly. The following parameters were evaluated: moisture content (LVS ISO 1442:197), protein content (LVS ISO 937:1978), fat content (LVS ISO 1443:1973), ash content (ISO 936:996), degree of liking, and intensity of sensory properties (ISO 4121: 2003). The smallest changes in moisture content among the studied samples were observed in those prepared with the fruit-vegetable additive if compared to a raw fillet. In the process of heat treatment, the protein content in dry matter of broiler and hen fillet decreased (p<0.05), whereas fat content decreased in broiler fillet but increased in hen fillet (p<0.05). Sensory evaluation results showed that panellists preferred broiler fillet (6.6) and hen fillet (5.8) products which were prepared without the fruit-vegetable additive. Evaluation of the intensity of sensory properties showed that there do not exist significant differences in aroma, colour, flavour, and aftertaste of heat-treated vacuum-packaged hen and broiler fillet (p>0.05), but texture of broiler fillet products is more tender than texture of samples made from hen fillet.

The Effects of the Withdrawal Rate and Heat Treatment on the Microstructure of Directionally Solidified Nb-14Si-24Ti Alloy

2013 ◽  
Vol 32 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Ligang Wang ◽  
Fei Ding ◽  
Sainan Yuan ◽  
Lina Jia ◽  
Hu Zhang
Keyword(s):  
Heat Treatment ◽  
Volume Fraction ◽  
Metastable Phase ◽  
Withdrawal Rate ◽  
Eutectoid Reaction ◽  
Eutectic Cell ◽  
Directionally Solidified ◽  
Rich Phase ◽  
Heat Treated ◽  
Granular Morphology

AbstractIn this work, an Nb-14Si-24Ti alloy (at.%) was prepared by liquid-metal-cooled directional solidification (DS) and then heat treated (HT) at 1450°C for 100 h. The effects of the withdrawal rate and heat treatment on the microstructure were investigated. The results show that the DS samples consisted of NbSS dendrites, Nb3Si blocks and eutectic NbSS/Nb3Si. As the withdrawal rate increased, the microstructure became finer, the volume fraction of eutectic NbSS/Nb3Si increased and the morphology of eutectic cell transformed from petaloid to regularly arranged granular morphology. The microstructure of the HT samples consisted of NbSS and Nb3Si. The metastable phase of Nb3Si did not discompose through the eutectoid reaction. The dendritic NbSSconnected through diffraction and the secondary dendrite arm got coarser. The boundary of eutectic NbSS/Nb3Si became blurry and the black Ti-rich phase of the DS samples in this region disappeared. The Nb3Si connected to form the continuous matrix. The granular NbSS of eutectics spheroidized and the lamellar NbSS of eutectic interconnected and became more bending distributed uniformly in the Nb3Si matrix.

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