Local Composition Migration Induced Microstructural Evolution and Mechanical Properties of Non-equiatomic Fe40Cr25Ni15 Al15Co5 Medium-Entropy Alloy

A newly designed composition of non-equiatomic Fe₄₀Cr₂₅Ni₁₅Al₁₅Co₅ medium-entropy alloy (MEA) was produced by induction melting (IM). The as-cast alloy was found to consist of a two-phase microstructure of BCC (2.87 ± 0.01 Å) and ordered B2 (2.88 ± 0.02 Å) type phases. The structures of these phases were confirmed through X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. It was observed that the Ni-Al-enriched ordered B2 phase of cuboidal shapes (~ 100 to 200 nm) is homogeneously distributed in Fe-Cr-rich BCC matrix with a cube-on-cube orientation relationship. The formation of the columnar dendrites (width 50 to 100 μm) was identified through optical microscopy (OM). The structural and microstructural stability of the alloy was investigated by heat-treating the alloy through different schedules. Heat-treated samples at different temperatures (< 1273 K) exhibit a similar type of two-phase microstructure with columnar dendrites. However, compositional rearrangement takes place during long time exposure to develop polymorphically related phases. The alloy was observed to possess a high compressive yield strength and hardness, i.e., ~ 1047 MPa and 391 ± 9 HV, respectively, at room temperature. Heat-treated samples at 600 °C and 900 °C (873 K and 1173 K) showed an increase in yield strength and ultimate strength with a significant increase in plasticity due to the increase in volume fraction of B2 phase and softening of the BCC matrix phase. The thermal stability and high strength of this alloy may open new avenues for high-temperature applications.

     

IoT-based hydrological monitoring of water-induced landslides: a case study in central Norway

Bulletin of Engineering Geology and the Environment - Given the limited dissipating effect and high construction costs of traditional sand cushion in shed, this paper proposes to partially replace...     

Status, Prospects & Perspectives of Indian Paper Industry

Indian paper industry has been showing a positive demand growth unlike Europe and USA, despite couple of issues being confronted by the paper industry such as availability of good quality raw material, scale of operation, cost reduction and environment. In view of the increasing competition among the domestic and the global players, sustainability, green production gaining significance, there is a growing need to upgrade, develop and adopt appropriate advanced technologies tailer made to the requirement of Indian paper industry. In light of above, UNIDO implemented a project supported by DIPP, Govt. of India aimed towards capacity building of the Nodel Research Institute (CPPRI), Indian paper industry’s associations and Indian paper industry. The present article highlights key findings of various activities carried out under the project such as diagnostic assessment of the paper industry, demonstration of identified technologies, dissemination of the findings among the industries and twinning with the international institutions having relevant expertise and training.     

Physico-chemical,mechanical and electrical performance of bael fruit gum–chitosan IPN films

The gum obtained from unripe fruits of Aegle marmelos was co-processed with chitosan to improve the film forming property of the former. The results of FTIR and differential thermal analysis of films revealed maximum interaction between –COO⁻ groups of gum and –NH₃⁺ of chitosan when they were present in equal proportion in the film. These films exhibited almost negligible zeta potential and the surface remained smooth after exposure to both acidic and alkaline pH as observed under scanning electron microscope. The contact angle and swelling index of this film in both acidic and alkaline buffers were observed to be lowest as compared to other films prepared with different ratios of gum and chitosan. The work of adhesion and spreading coefficient for this film was observed to be lowest. These results could be attributed to optimum interaction between –COO⁻ groups of gum and –NH₃⁺ groups of chitosan. These results indicated the ability of this film for use in modifying drug release and processed food items.     

Mechanical and Thermal Properties of Thermoset–Graphene Nanocomposites

Graphene has resulted in significant research effort to generate polymer nanocomposites with improved mechanical, thermal as electrical properties as compared to pure polymers. A large number of studies have been undertaken using different graphene derivatives, filler loadings, synthesis methods, and so on to obtain optimum filler dispersion as well as filler–matrix interactions, which are crucial for achieving significant enhancement in the properties, especially at low filler fraction. This review summarizes the mechanical and thermal properties of numerous studies carried out for the property enhancements of commercially relevant thermosetting materials such as epoxy, polyurethane, natural rubber, melamine formaldehyde, phenol formaldehyde, silicones, vinyl ester, cyanate ester, and unsaturated polyester resin.

     

Effect of maleated polypropylene as a compatibilizer and hyperbranched polyester as a processing aid on polypropylene‐wood flour biocomposites

This work focused on two difficulties associated with preparation of polypropylene/wood flour (PP/WF) composites, viz. the compatibility of PP with WF and processing of the composites with high melt viscosity. Maleic anhydride‐grafted polypropylene (MAPP) was used in the preparation of PP composites to provide the compatibility between polymer and filler. Hyperbranched polyester (HBPE) was incorporated to check feasibility of it as a processing aid in the same. The PP/WF composites were formulated by melt compounding on a Brabender Plastograph EC. Blending effect of compatibilizer and processing aid HBPE on PP/WF biocomposites have been carried out on the basis of torque analysis, mechanical properties, morphology, and thermal stability. The investigation showed that HBPE improves the processibility of PP/WF composites than MAPP with respective to torque value. The mechanical and thermal properties slightly vary with change in relative proportion of MAPP and HBPE. J. VINYL ADDIT. TECHNOL., 24:179–184, 2018. © 2016 Society of Plastics Engineers