Quantitative estimation of corrosion rate in 3C steels under seawater environment

An artificial neural network method is proposed to correlate the relationship between the corrosion rate of 3C steels with seawater environment factors. The predictions with the unseen test data are in good agreement with experimental values. Further, the developed model used to simulate the combined effect of environmental factors (temperature, dissolved oxygen, salinity, pH values, and oxidation-reduction potential) on the corrosion rate. 3D mappings remarkably reveal the complex interrelationship between the input environmental parameters on the output corrosion rate. The quantitative estimation of corrosion by virtual addition/subtraction of environmental factors individually to a hypothetical system helps to understand the impact of each parameter

Review of experimental methods to determine spontaneous combustion susceptibility of coal – Indian context

This paper presents a critical review of the different techniques developed to investigate the susceptibility of coal to spontaneous combustion and fire. These methods may be sub-classified into the two following areas: (1) Basic coal characterisation studies (chemical constituents) and their influence on spontaneous combustion susceptibility. (2) Test methods to assess the susceptibility of a coal sample to spontaneous combustion. This is followed by a critical literature review that summarises previous research with special emphasis given to Indian coals

Doping-induced coloration in titania

Thermal decomposition of Ti3GeC2 MAX phase at 1773 K yields an orange-colored titania powder. Micro-XRD of the powder under oscillation mode reveals a pure rutile phase (space group P42/mnm). X-ray photoelectron spectroscopy confirmed substitutional doping of Ge in the titania lattice. The presence of Ti-O-Ge bond was observed in O 1s spectrum and confirmed by the shift in binding energy in Ti 2p3/2 and Ge 3d peaks. The UV-visible Diffuse Reflectance Spectrum studies on the Ge-doped titania powder show wide absorption in the visible region (380 to 650 nm) yielding a bandgap of 2.83 eV, which is desirable for photocatalytic applications. Defect states formed due to Ge doping led to lowering of the titania conduction band inducing an orange coloration in the powder. © 2021 The American Ceramic Societ

Effect of Cr2AlC MAX phase addition on strengthening of Ni-Mo-Al alloy coating on piston ring: Tribological and twist-fatigue life assessment.

The aim of the present study is to investigate the effect of Cr2AlC additions on the tribological properties of Piston Ring coated with Ni-Mo-Al alloy. For this Cr2AlC MAX phase was blended with Ni-Mo-Al alloy powder in different proportions (10 wt%, 20 wt% and 50 wt%) and coated on the stainless steel piston ring by Air Plasma Spraying (APS). During coating Cr2AlC MAX reacts with air and forms Cr7C3 and Al2O3 phases. The in-situ formation of Cr7C3 and Al2O3 was observed to strengthen the alloy. 20 wt% Cr2AlC additions to the Ni-Mo-Al alloy yields a good combination of properties, such as improved adhesion, hardness and wear resistance. Composite coating was found to be stable during the exfoliation test of the coated ring. Coating life cycles were found to be nearly doubled by MAX phase addition, as assessed through the twist-fatigue study. These improved properties could be attributed to the finely distributed oxides (alumina) and chromium carbides (Cr7C3) within the coated layer, which were formed in-situ during plasma spraying

Corrigendum to “Quantitative estimation of corrosion rate in 3C steels under seawater environment” [J Mater Res Technol vol. 11 (March–April 2021) 681–686]

The authors regret to inform you that there are two corresponding authors for this article (B.B. Panigrahi and N. S. Reddy). Corresponding authors: 1. B.B. Panigrahi, 040-23016555, [email protected] 2. N. S. Reddy, 055-7721669, [email protected]

Some effects of particle size on the sintering of titanium and a master sintering curve model

The press-and-sinter method of producing net shapes was applied to titanium alloys. The quantitative effects of the particle size of titanium and Ti-6Al-4V powders on the green and sintered densities were examined. Most powders were pressed at 100 to 800 MPa and sintered under vacuum at 1100 °C, 1200 °C, or 1300 °C for 2 hours. The green density was higher for coarser powders and for powders with a wider size distribution. The sintered density was higher for finer powders and for powders with a wider size distribution. The densification parameter was little affected by the compaction pressure but increased as the particle size was reduced. An empirical model of densification based on the master sintering curve approach was developed, with the activation energy for densification of titanium found to be approximately 160 kJ/mol