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Journal of Materials Science Research
Number of Followers: 8  Open Access journalISSN (Print) 1927-0585 - ISSN (Online) 1927-0593 Published by CCSE  [43 journals]
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- Canola Meal Adhesive for the Production of Wood Fiber Insulation Boards
Using Hot-Air/Hot-Steam-Process
Abstract: Canola meal as a by-product from the vegetable oil production provides a protein-rich material which is available in large quantities but with limited areas for application. The objective of this study was to investigate the possibility of utilizing canola meal adhesive for the production of wood fiber insulation boards (WFI) using the hot-air/hot-steam-process. WFI with two different thicknesses (40/60 mm) and different densities (110/140/160/180 kg/m³) were manufactured. The testing focused on their physical-mechanical properties such as internal bond strength (IB), compressive strength (CS) and short-term water absorption (ST-WA) measured according to European standards. For a better understanding of the material and curing dynamics, the canola meal was analyzed on its protein content, lignin and pentosane content as well as its extractives content using hot water, cold water and successive extraction. Using a canola meal based adhesive resulted in promising results for IB and CS up to density of 140 kg/m³. Nonetheless, there is place for improvement for the ST-WA.
PubDate: Mon, 05 Jul 2021 23:44:54 +000
- Analysis on Degradation in Creep Strength of 9Cr-W Martensitic Steel
Abstract: In order to clarify the creep mechanism of high Cr martensitic steel, creep curves of 9Cr-1W and 9Cr-4W steels were analyzed applying an exponential law to the temperature, stress, and time parameters. The activation energy, Q
, the activation volume, V
, and the Larson-Miller constant, C
, are obtained as functions of creep strain. At the beginning of creep, sub-grain boundary strengthening by swept dislocations out of sub-grains occurs followed by strengthening due to the rearrangement of M23C6 and the precipitation of Laves phase. After Q reaches a peak, heterogeneous recovery and subsequent heterogeneous deformation begin at an early stage of transient creep in the vicinity of some weakest boundaries due to coarsening of the precipitates, which triggers the unexpected degradation in strength due to the accelerating coarsening of precipitates. Stabilizing not only M23C6 but also Laves phase is important to mitigate the degradation of rupture strength of martensitic steel. The above creep mechanism for martensitic steel can be applicable to the explanation for the degradation in long term rupture strength of high Cr martensitic steel, Grades 91 and 92.
PubDate: Mon, 05 Jul 2021 23:43:13 +000
