Influence of Hydrophobic Agent on Rheological Behavior of Historical Plaster. Part 1: Initial Hardening Time

2018 ◽  
Vol 776 ◽  
pp. 127-132
Author(s):  
Radka Pernicova
Keyword(s):  
Rheological Properties ◽  
Flow Characteristic ◽  
Strain Rates ◽  
Comparative Measurement ◽  
Flow Curves ◽  
Hydrophobic Agent ◽  
Lime Plaster ◽  
Rheological Test ◽  
Short Times

The influence of time on rheological properties of modified lime plaster is analyzed in this paper. Effect of composition of mixture is examined as well. Especially changes of paste due to hydrophobic and pozzolanic admixture. Main aim of rheological test is determination of flow curves, obtained by applying a succession of constant strain rates for short times. Base on performed experiments, it can be concluded that hydrophobic admixture eliminated influence of pozzolana. Also both time and temperature caused significant changes in rheological properties. Increasing values decreases the flow characteristic of the plaster. A comparative measurement with pure lime plaster was done as well.

Influence of Hydrophobic Agent on Rheological Behavior of Historical Plaster. Part 2: External Temperature

2018 ◽  
Vol 776 ◽  
pp. 133-139
Author(s):  
Radka Pernicova
Keyword(s):  
Rheological Properties ◽  
Strain Rates ◽  
Comparative Measurement ◽  
Flow Curves ◽  
External Temperature ◽  
Hydrophobic Agent ◽  
Lime Plaster ◽  
Rheological Test ◽  
Short Times

In a previous study, we presented new method measurement rheological properties of hydrophobized plaster in dependence of hardening time. Influence of external temperature on pozzolana plaster is analyzed in this paper, especially plasticity and workability of paste. Main aim of rheological test is determination of flow curves, obtained by applying a succession of constant strain rates for short times at the temperature 10°C and 30°C. Base on the performed experiments, it can be concluded that the temperature have very significant influence on rheological properties of plasters. With an increase in temperature, the application time of the mixture is shorter, from hour to minutes. A comparative measurement with pure lime plaster was done as well.

Determination of Rheological Properties of Titanium Alloys under Conditions of High Strain Rates

2016 ◽  
Vol 684 ◽  
pp. 222-226 ◽  
Author(s):  
Andrey V. Balaykin ◽  
Alexsandr I. Kondratev ◽  
Natalia V. Galkina
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
Rheological Properties ◽  
High Strain ◽  
Aircraft Engine ◽  
Face Milling ◽  
Strain Rates ◽  
Fem Model ◽  
Cae System

This article considers the method of determining the parameters of the rheological properties of material of titanium alloy BT6 used in aircraft engine technology, under face milling. Calculations were carried out in CAE system Deform using FEM - model.

Influence of trisilanol isooctyl POSS content on the structure, morphology and rheological properties of thermoplastic polyurethane (TPU)

2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
Thermoplastic Polyurethane ◽  
Reactive Extrusion ◽  
Strain Rates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extensional Strain ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.

Characteristics of Dynamic Recrystallization during Hot Deformation for High Nitrogen Stainless Steels

2012 ◽  
Vol 715-716 ◽  
pp. 115-121
Author(s):  
Hai Wen Luo ◽  
Xu Dong Fang ◽  
Rui Zhen Wang ◽  
Zhan Yin Diao
Keyword(s):  
Dynamic Recrystallization ◽  
Stainless Steels ◽  
Hot Deformation ◽  
Strain Rates ◽  
Peak Strain ◽  
High Nitrogen ◽  
Flow Curves ◽  
Grain Sizes ◽  
Nitrogen Contents ◽  
High Nitrogen Stainless Steel

Dynamic recrystallization was studied for the stainless steels with nitrogen contents of 0.56% to 1.08% during hot deformation at temperatures of 900~1200 with strain rates ranging from 0.003 to 42 s-1. It was found that flow stress could increase remarkably with increasing nitrogen content. Flow curves during the deformation by 0.1~42/s at temperatures of 900~1200°C show a single peak, indicating the occurrence of dynamic recrystallization during deformation. The peak strain seems to decrease with increasing N content, suggesting that higher content of N facilitates dynamic recrystallization. The quenched microstructures were analyzed by optical microscopy, EBSD and TEM. The recrystallized grain sizes on the quenched specimens were measured and its dependence on temperature and strain rate was analyzed. At high temperature, continuously dynamically recrystallized microstructures were observed; whilst at low temperature, necklace-like partially recrystallized microstructures were found. Key words: High nitrogen stainless steel; dynamic recrystallization; stress-strain curves

Sign in / Sign up

Export Citation Format

Share Document