04/01598 Change in viscosity of softening coal upon heating with its liquid content. Part II. Examination of rheological property and phase structure of softening coal

2004 ◽  
Vol 45 (3) ◽  
pp. 217
2013 ◽  
Vol 815 ◽  
pp. 898-904
Author(s):  
Xiu Li Hu ◽  
Wei Liang Zhou ◽  
Le Qin Xiao ◽  
Xiao Xia Jian

The rheological properties of HTPB mixed with boron (B) or agglomerated boron (TB) were investigated to explore the effect of the impurities of boron on the processing of propellant. The phase structure, morphology, and acidity of each sample were characterized by XRD, SEM and pH, respectively. The results show that rheological property of B/HTPB can be significantly improved by agglomerating boron with binder. Time has little effect on the viscosity of TB/HTPB while that of B/HTPB is a strong function of time. The viscosity of TB/HTPB decreases when the temperature increases from 303K to 343K, while that of B/HTPB decreases from 303K to 323K and then increases sharply after 323K. After agglomerating with binder, theTonsetof boron reduces from 1056K to 954K andTpdrops from 1076K to 998K. Compared with B2, the weight gain and oxidation degree of TB2 increases by 27% and 8.5%, respectively.


2020 ◽  
pp. 130-135
Author(s):  
D.N. Korotaev ◽  
K.N. Poleshchenko ◽  
E.N. Eremin ◽  
E.E. Tarasov

The wear resistance and wear characteristics of cluster-gradient architecture (CGA) nanostructured topocomposites are studied. The specifics of tribocontact interaction under microcutting conditions is considered. The reasons for retention of high wear resistance of this class of nanostructured topocomposites are studied. The mechanisms of energy dissipation from the tribocontact zone, due to the nanogeometry and the structural-phase structure of CGA topocomposites are analyzed. The role of triboactivated deformation and diffusion processes in providing increased wear resistance of carbide-based topocomposites is shown. They are tested under the conditions of blade processing of heat-resistant titanium alloy.


2019 ◽  
Vol 92 (10) ◽  
pp. 1342-1350 ◽  
Author(s):  
V. N. Strel’nikov ◽  
V. Yu. Senichev ◽  
A. I. Slobodinyuk ◽  
A. V. Savchuk ◽  
E. V. Pogorel’tsev

2000 ◽  
Vol 65 (11) ◽  
pp. 1820-1832
Author(s):  
Miloslav Pekař ◽  
Pavel Kopecký

Rheokinetics of polybutadiene-based polyurethanes was studied. Sixteen mixtures differing in the miscibility of reactive components and hard segments contents were prepared. Regardless of the miscibility of the components, the rheokinetics behaviour is qualitatively very similar. The viscous response part is formed and finished much earlier than the elastic part. The quantitative dissimilarities, caused by cooperative effect of miscibility and differences in reactivity, are described. Using a well miscible initial mixture need not give the best results as a reactive crosslinker can easily react with isocyanate and separate from the rest of the reaction mixture thus impairing the final phase structure.


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