Data mining has revolutionized sectors as diverse as pharmaceutical drug discovery, finance, medicine, and marketing, and has the potential to similarly advance materials science. In this paper, we describe advances in simulation-based materials databases, open-source software tools, and machine learning algorithms that are converging to create new opportunities for materials informatics. We discuss the data mining techniques of exploratory data analysis, clustering, linear models, kernel ridge regression, tree-based regression, and recommendation engines. We present these techniques in the context of several materials application areas, including compound prediction, Li-ion battery design, piezoelectric materials, photocatalysts, and thermoelectric materials. Finally, we demonstrate how new data and tools are making it easier and more accessible than ever to perform data mining through a new analysis that learns trends in the valence and conduction band character of compounds in the Materials Project database using data on over 2500 compounds.

This paper, for the first time, reports the results of microwave sintering of two emerging biomaterials, magnesium phosphate and amorphous magnesium calcium phosphate. Beneficial aspects of successful microwave sintering of calcium phosphate are well documented in the literature. The motivation for this work derives from the absence of any publication of similar nature on magnesium phosphates, which are becoming important with the rapid rise in interest in biodegradable Mg-alloys. Starting off with amorphous calcium magnesium phosphate and magnesium phosphate, the resulting microwave sintered product is a biphasic mixture of whitlockite substituted with magnesium and magnesium phosphate. The influence of the extent of Mg substitution on the mechanical properties, microstructure, and sintering behavior of tricalcium phosphate was evaluated. The results showed that the addition of Mg (up to the 50% wt/wt in relation to Ca mass) in the precursor compound of magnesium calcium phosphate improved the kinetics of the densification process and enhanced hardness values.

A scale formed by heat treatment of Ti in a nitrogen atmosphere containing oxygen at an extremely low partial pressure exhibited an exceptional degree of hydroxyapatite (HAp) formation in a simulated body fluid. Scanning transmission electron microscopy and electron energy loss spectroscopy indicated that the subsurface of this scale was composed of nitrogen doped rutile-type TiO2. The N-K edge energy-loss near edge structure spectrum of this layer in conjunction with the theoretical spectra of possible compounds obtained using the augmented plane wave plus local orbital band method suggested that oxygen sites were replaced by two nitrogens, resulting in an effective charge of +2. The enhanced HAp forming ability of this scale is likely related to the positively charged surface induced by the presence of N. Conversely, the subsurface scale formed by heat treatment in air, in which N is not found, leads to much slower HAp coverage, believed to be related to the lack of surface charge.

In this work, the selective removal of ions from multicomponent mixtures using functionalized magnetic nanoparticles (FMNPs) was demonstrated. As, Sb, and Se ions were efficiently removed from complex mixtures, such as Rhodiola rosea extracts and influent water from the sewage treatment unit of a beer brewery. As, Sb, and Se ions could be selectively adsorbed by FMNP, as demonstrated by the inductively coupled plasma mass spectrometer analyses. We also demonstrated that Pb ions are weakly adsorbed, whereas Cu, Cd, and Zn ions cannot be adsorbed by FMNP. The complexity of the mixture did not affect the selective removal of As, Sb, and Se ions. FMNP could be recycled and used repeatedly. Magnetic separation could then be applied for the selective separation of complex mixtures, such as plant extracts, industrial wastewater, and tap water.

The refractory nature of BaTiO3 leads to limited densification and grain growth for films processed at low temperatures and a modest nonlinear dielectric response due to a marked sensitivity to physical scale and material quality. Adding liquid-forming sintering aids, common in bulk ceramics, to thin films enhances mass transport, leading to enhanced grain growth at lower temperatures. This work explores the effectiveness of a sputtered CuO buffer layer with BaO–B2O3 (BBO) fluxes to engineer the microstructure of BaTiO3 films. Grain size and homogeneity increase in the presence of even a ∼1 nm CuO layer. In general, grain size increases from 75 to 370 nm with an addition of 2.2% BBO and 8 nm CuO. Room temperature capacitance in fluxed films increases by a factor of 5 over pure films, and ferroelectric phase transitions are clearly observable in dielectric measurements. CuO–BBO proves effective on (0001) Al2O3 and (100) MgO substrates, although all microstructures are notably finer for the latter.

Diamond like carbon (DLC) films deposited using CH4 and Ar and amorphous fluorocarbon (a:C-F) films deposited using CF4 and Si2H6 as precursors were optimized for ultra-low dielectric constant applications by tuning pressure, substrate temperature, and flow rate ratio. Sixty three films belonging to three stack configurations possessed good morphology and adhesion post DLC deposition. Structural and mechanical properties with respect to film integrity, adhesion, roughness, and shrinkage rate were studied. Internal and interface stress distribution results in the increased stability of as deposited DLC–a:C-F–DLC sandwich layers in comparison to a:C-F–DLC stacks. Annealed a:C-F with DLC top coat and As deposited a:C-F are similar in bonding structure. Failure mode is buckling delamination failure with increasing severity in films with higher oxygen incorporation and can be preserved by annealing the fluorocarbon component or providing a DLC base coat. Effect of process parameters on properties relevant to integration has been determined.

The double perovskite Tb2MnCoO6 and two simple perovskites TbMnO3 and TbCoO3 were synthesized by a solid sintering reaction method. The Rietveld refinement results based on the x-ray powder diffraction data identified all samples as orthorhombic perovskite structures with space group Pbnm (62). The lattice parameters of Tb2MnCoO6 were a = 5.278 (3) Å, b = 5.579 (4) Å, and c = 7.513 (4) Å with a cell volume V = 221.2 (6) Å3, Z = 2. Meta-magnetic behavior was observed near 92 K for Tb2MnCoO6, which was considered to be related to the coexistence of and competition between the ferromagnetic order and antiferromagnetic order. Temperature-dependent resistance (R–T) was also measured. Compared with TbCoO3 and TbMnO3, Tb2MnCoO6 is more conductive, with its activation energy reduced from 0.3062 eV for TbCoO3 (0.2754 eV for TbMnO3) to 0.1949 eV. The results reported here can assist in understanding the multiferroic physics mechanism of double perovskite materials.

Zinc(tris) thiourea sulphate (ZTS) is as one of the potential candidates for nonlinear optical applications due to its high nonlinearity and excellent optical properties. The synthesis of pure and titan yellow dye doped ZTS has been done and good quality rod-like single crystals of size ∼60 mm long and 2 mm diameter were grown through simplest and low cost route. The structural and vibrational analysis rules out any extra phase or change in structure of ZTS due to dye doping. Scanning electron microscope study reveals that the grown crystals are of good quality with rod-like morphology. Diffuse reflectance spectrum show a new absorption band at ∼460 nm, which may be predicted as a signature of dye. The optical band gap was calculated to be 4.6 eV for pure and 4.5 eV for doped ZTS crystals. The violet-blue emission centered at 412 nm in pure and at 414 nm in doped crystals with an additional green emission bands at 528 nm with high intensity in the photoluminescence spectra were observed. The value of ε1 is found to be enhanced from 10 (in pure) to 14 (in doped) crystals. The properties are enhanced due to dye doping and may be more useful than pure crystals in optoelectronic devices.

Potassium dihydrogen phosphate (KDP) is an important nonlinear optical crystal material for light frequency converters and Pockels photoelectric switches in laser systems. However, KDP is apt to fracture, is deliquescent, and can suffer from microstructural changes under a temperature variation. As such, KDP has been one of the most difficult-to-handle materials, but its properties have not been well understood. This paper aims to explore the mechanical properties of KDP crystals in detail with the aid of the nanoindentation technique using a Berkovich diamond indenter. It was found that the mechanical properties of KDP can be easily altered by machining-induced subsurface damage. It was also discovered that a KDP crystal is a visco-elasto-plastic material during micro/nanoscale deformation, although it is very brittle macroscopically.

Tungsten oxide (WO3−x) nanomaterials with controlled morphology and composition were fabricated by thermal evaporation of WO3 and S powders at different temperatures in a vacuum tube furnace. At 850 °C the obtained green particle is still of the same monoclinic WO3 phase as that of the starting powder. At a temperature between 900 and 1100 °C, the resultant dark-blue products are particle-like clusters composed of numerous monoclinic WO2.90 short nanorods, but the clusters became looser and the nanorods grew somewhat longer as the temperature increased. At a temperature between 1150 and 1250 °C, elongated and thoroughly separate purple-red monoclinic W18O49 nanorods were obtained. The growth of the prepared WO3−x nanomaterials was controlled by a gas–solid mechanism. Their photocatalytic degradation on organic contaminants was evaluated by decomposing methylene blue (MB) in aqueous phase under sunlight, in which WO3 particles presented higher photocatalytic activity than its oxygen-deficient counterparts, WO2.90 and W18O49. But the W18O49 nanorods had higher adsorption ability to MB in all the samples.

Hot compression tests on pure Ni and Ni–30Cu at 950–1150 °C and strain rates of 0.001–1 s−1 were performed to identify the physical interpretation of the apparent activation energy (Qd). For pure Ni, Qd was constant and identical to that of the self-diffusion. However, for Ni–30Cu, it decreased steadily with strain. The value of Qd was separated into thermal and mechanical parts. The thermal part was necessary to propel diffusion. For pure Ni, the mechanical part was zero at low and medium strain rates of 0.001–0.1 s−1 and the self-diffusion was the controlling mechanism. However, at 1 s−1, both the thermal and mechanical parts were needed to provide Qd. For Ni–30Cu, Qd was greater than that for the interdiffusion of Ni and Cu. The value of mechanical part decreased with increasing temperature and strain rate. Although the thermal parts for pure Ni and Ni–30Cu were nearly identical, the mechanical part for the latter was considerably higher. The difference was attributed to the strengthening effect of Cu atoms and the sluggish dynamic softening with respect to pure Ni.

In this study, we report a micropillar stress relaxation technique employing a stable displacement-controlled, in-situ scanning electron microscope indenter, and unusually large micropillars to precisely measure stress relaxation in electroplated nanocrystalline Ni thin films. The observed stress relaxation is significant under constant displacement: even well below the 0.2% offset yield strength, the stresses relax by ∼4% within a minute; in the work hardening regime, stress relaxes by ∼9% in 1 min. A logarithmic fit of the relaxation curves is consistent with an Arrhenius thermal activation of plasticity and suggests an activation volume in the vicinity of ∼10 b3. The apparent and effective activation volumes diverge at lower strains, particularly in the “elastic” regime. These measurements are compared to similar measurements performed on free-standing thin film tensile coupons. Both methods yield similar results, thereby validating the applicability of pillar compression to capture time-dependent plasticity. To our knowledge, these are the first micropillar stress relaxation experiments on metals ever reported.

Mechanics of deformation in miniaturized indirect extrusion (IE) and their resulting process outcomes are shown to be dependent on the dimensional scale of the plastic deformation zone. Using optically transparent dies as prototypes, the effect of process length-scales on the strain, strain-rate, and rotation fields is elucidated using digital image correlation. In this regard, in situ experiments were performed on commercially pure Lead (Pb) and Aluminum (Al 1100) as prototypical nonwork/work hardening materials. By overlaying these measurements with microstructural characterization via electron backscattered diffraction, the effect of deformation volume on process–structure mappings is identified. Herein, visco-plastic self-consistent framework-based modeling of the evolution of crystallographic textures was investigated to achieve insights into the trajectories of microstructure evolution and process outcomes during IE. These findings provide a beneficial background about characteristics of plastic deformation zone and its distribution to optimize and control the properties of miniaturized components.

The influence of temperature and strain rate on hot deformation behavior and microstructure of Cu–10Ni–3Al–0.8Si alloy was investigated. The true stress increased rapidly initially until it approached the peak values. The peak value of true stress and the Zener–Hollomon parameter decreased with the increase of temperature and the decrease of strain rate. The thermal activation energy of the alloy was about 396.57 kJ/mol, the processing map was established and the appropriate compression temperature was between 900 and 950 °C. The 〈001〉 and 〈011〉 fiber texture was the main type of texture. The increase of temperature or strain rate accelerated the formation of 〈001〉 fiber texture. Dynamic recrystallization nucleated and deformation bands formed at 750 °C. Recrystallization was accelerated with the increase of temperature and the decrease of Zener–Hollomon parameter. Both continuous recrystallization resulting from dynamic recovery and dynamic discontinuous recrystallization were softening mechanisms.

The effect of solution treatment (ST) on the microstructure and mechanical properties of cast Al–3Li–1.5Cu–0.2Zr alloy was investigated. Results showed that the volume fraction of secondary phases (Al2Cu, Al3Li) decreased obviously after ST. It was found that the strengthening of Al–3Li–1.5Cu–0.2Zr alloy was a balance of the precipitation strengthening, residual phase strengthening and fine grain strengthening. The residual phase strengthening and fine grain strengthening decreased with increasing the solution temperature and time, while precipitation strengthening increased. After ST at 560 °C for 40 h, the elongation of Al–3Li–1.5Cu–0.2Zr alloy reaches the highest value of 22.1%. In addition, the tensile properties are up to the highest values, ultimate tensile strength of 359 MPa and elongation of 3.5% after optimal ST at 560 °C for 40 h followed by aging treatment.

The effects of different Gd additions on wear behavior of the T6 heat treated Mg–xGd–3Y–0.5Zr alloys were investigated. The wear tests were carried out using a Ball-on-flat type wear apparatus against an AISI 52100 type bearing steel ball counterface in the load range of 3–15 N, sliding speed range of 0.03–0.18 m/s, temperature range of 25–200 °C and at a constant sliding distance of 400 m. The results showed that the wear rate of the tested alloys increased with increasing sliding load. By increasing the wear temperature to 200 °C, the wear rate of the Mg–6Gd–3Y–0.5Zr alloy decreased by about 24%. At higher wear speeds, wear resistance of the alloys increased due to the formation of stable oxide layers on the worn surfaces. The alloy containing 12 wt% Gd exhibited higher wear resistance compared with the alloys containing lower Gd contents under the same conditions.

The tin–bismuth eutectic alloy possesses anomalous physicochemical properties that are dependent on temperature. This paper reports the interfacial reaction and growth behavior of the intermetallic compound (IMC) layer during the dissolution of solid copper in liquid eutectic tin–bismuth at 673–823 K under the influence of the structural transition of liquid eutectic tin–bismuth. The structural transition markedly affected the dissolution rate constant of solid copper and the growth rate of the IMCs. Correspondingly, the application of the liquid structural transition significantly decreased the activation energy of dissolution and increased the apparent activation energy for IMC growth. Moreover, two major roles of elemental Bi on the formation and growth of the IMCs were suggested.

A research was carried out to investigate the microstructures and mechanical properties of high Mn containing Al–5Mg–Mn alloys cast under near-rapid cooling. The results indicated that the mechanical properties of the hot bands and cold rolled sheets were remarkably improved with Mn content increasing to 1.6 wt%. The near-rapid cooling process greatly refined the intermetallic constituents. The intermetallic Al6(Fe,Mn) particles found in the hot bands were rare and small when the content of Mn was hypoeutectic. In the samples with higher Fe and Si content, a large amount of Al6(Fe,Mn) and Mg2Si particles remained in the hot bands. But the hot bands still showed better mechanical properties due to the refinement of the intermetallic constituents by the near-rapid cooling process. The results were of commercial interest to the production of AA5083 alloy via continuous strip casting process.

Effects of annealing temperature on stress corrosion susceptibility of AA5083–H15 alloys were studied by annealing specimens at 150, 200, 250, 300, and 350 °C before sensitization. Nitric acid mass loss testing and slow strain rate testing were conducted to investigate intergranular corrosion (IGC) and stress corrosion cracking (SCC). Results indicate that H15 alloy was less susceptible to IGC, but this alloy had the highest susceptibility to IGC and SCC after sensitization. Due to the continuous precipitation of β phase, the sensitized 150 and 200 °C alloys were highly susceptible to IGC and SCC. The 250 °C alloy was less susceptible to IGC because of the absence of the precipitation of β phase. After sensitization, this alloy was also less susceptible to IGC and SCC on account of the discontinuous precipitation of β phase. The sensitized 300 and 350 °C alloys were susceptible to IGC but less susceptible to SCC because of their lower strength and higher elongation.