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Master curve and reference temperature (T0) from three-point bending specimens of 20MnMoNi55 steel for different thicknesses and a/W ratios are determined using Kim Wallin’s master curve methodology (ASTM E1921-02) to study the effect of variation in thickness and a/W ratio at reference temperature (T0). Weibull stress at the crack tip is calculated from FE analysis of each fracture test using FE software ABAQUS. Calibration of Beremin parameters, like Weibull modulus (m) and scaling parameter (σu), and Cm,n is done using linear regression analysis of a large number of fracture test data at single test temperature. T0 for different thicknesses and a/W ratios are also evaluated from corresponding Weibull stress based on Beremin model using calibrated m, σu and Cm,n which are compared with experimental results showing case-specific good matching. The same calibrated values of Beremin parameters and Cm,n are also used to evaluate T0 for CT specimen of the same material using Beremin model, and an excellent matching with the experimental result is found.

Mechanical behavior of two-dimensional microstructures containing circular pores were simulated under uniaxial and biaxial loading using the finite element method. Resulting stress distributions were combined with classical fracture mechanics to investigate fracture behavior of brittle porous materials assuming that randomly oriented cracks are present along pore surfaces. Multiple crack orientations were found to introduce a variability in Weibull modulus even for the same set of microstructures containing equal number and size of cracks. Also, the variability increases with increasing crack size to pore size ratio. Under uniaxial loading, angular distribution of fracture origin widens with increasing porosity.

In this work, we examined the influence of different types of selective laser melting (SLM) devices on the microstructure and the associated material properties of austenitic 316L stainless steel. Specimens were built using powder from the same powder batch on four different SLM machines. For the specimen build-up, optimized parameter sets were used, as provided by the manufacturers for each individual SLM machine. The resulting microstructure was investigated by means of scanning electron microscopy, which revealed that the different samples possess similar microstructures. Differences between the microstructures were found in terms of porosity, which significantly influences the material properties. Additionally, the build-up direction of the specimens was found to have a strong influence on the mechanical properties. Thus, the defect density defines the material’s properties so that the ascertained characteristic values were used to determine a Weibull modulus for the corresponding values in dependence on the build-up direction. Based on these findings, characteristic averages of the mechanical properties were determined for the SLM-manufactured samples, which can subsequently be used as reference parameters for designing industrially manufactured components.

Three-dimensional (3D) printing is increasingly being utilized in the dental field. After fabricating a prosthesis using a 3D printed resin, a post-curing process is required to improve its mechanical properties, but there has been insufficient research on the optimal post-curing conditions. We used various 3D printed crown and bridge materials in this study, and evaluated the changes in their properties according to post-curing time by evaluating the flexural strength, Weibull modulus, Vickers hardness, color change, degree of conversion, and biocompatibility. The obtained results confirmed that the strength of the 3D printed resin increased when it was post-cured for 60–90 min. The Vickers hardness, the degree of conversion, and biocompatibility of the 3D printed resins increased significantly around the beginning of the post-curing time, and then increased more gradually as the post-curing time increased further. It was observed that the color tone also changed as the post-curing time increased, with some groups showing a ΔE00 value of ≥ 2.25, which can be recognized clinically. This study has confirmed that, after the printing process of a 3D printed resin was completed, a sufficient post-curing time of at least 60 min is required to improve the overall clinical performance of the produced material.

Zinc oxide is densified to 97% by the cold sintering process using an aqueous zinc acetate solution as the secondary transport phase. The mechanical response of the cold-sintered zinc oxide ceramics is investigated through the ball-on-three-balls biaxial bending technique. The analysis demonstrates that ZnO cold-sintered samples follow a Weibull distribution with a characteristic strength (σ0 ~ 65 MPa) and Weibull modulus (m ~ 8). Phase purity and residual secondary phases were analyzed via X-ray diffraction and Raman spectroscopy. This report provides an initial demonstration of the mechanical properties of cold-sintered parts in the as-pressed and unmodified state and serves for comparison with conventionally prepared ceramics.

Gel casting is an advanced wet-forming method for ceramics. In this paper, Isoabm 104 is selected as the dispersant and gelation agent for gel casting. The optimization of gel casting slurry and the preparation of the green and sintered alumina bodies are investigated. TAC reduces the viscosity of the slurry significantly due to electrostatic interaction. Isopropanol alcohol and vacuum tank eliminates the slurry’s air bubbles, thus improving the density of green bodies. A staged drying process is necessary to produce smooth and defect-free green bodies. After optimization of the slurry formulation and gel casting process, alumina ceramics with a Weibull modulus of 11.1 are successfully prepared.

The objective was to evaluate new commercially available ion-releasing restorative materials and compare them to established anti-cariogenic materials. Four materials were tested: alkasite Cention (Ivoclar Vivadent) in self-cure or light-cure mode, giomer Beautifil II (Shofu), conventional glass-ionomer Fuji IX (GC), and resin composite Tetric EvoCeram (Ivoclar Vivadent) as a control. Flexural strength, flexural modulus, and Weibull modulus were measured one day, three months, and after three months with accelerated aging in ethanol. Water sorption and solubility were evaluated for up to one year. Degree of conversion was measured during 120 min for self-cured and light-cured Cention. In this study, Beautifil II was the ion-releasing material with the highest flexural strength and modulus and with the best resistance to aging. Alkasite Cention showed superior mechanical properties to Fuji IX. Weibull analysis showed that the glass-ionomer had the least reliable distribution of mechanical properties with the highest water sorption. The solubility of self-cured alkasite exceeded the permissible values according to ISO 4049. Degree of conversion of light-cured Cention was higher than in self-cure mode. The use of alkasite Cention is recommended only in the light-cure mode.

Calcium carbonate is one of the most used raw materials in various industries, such as construction materials, food supplement, pharmaceutics, animal feed, plastic production, and others. Calcium carbonate can derive from marine wastes, like crustaceans and bivalve’s shells. The worldwide demand for new sources of food has increased exponentially, and following that tendency, the mariculture—especially the oyster culture—has been increasingly resorting to farming techniques. In 2016, 438 billion tons of oysters were produced. The majority of the shells were unduly discarded, presenting a public health problem. This article offers a solution based on the reuse and recycling of oyster shell residues in the production region of Florianópolis, SC, Brazil. The presented solution is an oyster shell by-product developed by a local company which produces artificial stone. The main component of the artificial stone is a composite material made of oyster shells incorporated in a polymeric resin. The mechanical properties, such as its flexural strength, hardness, Weibull modulus, and fracture analysis, were held in the artificial stone. The mechanical results of the new artificial stone were compared with other natural stones, such as granite and marble, and other commercial artificial stones. This material owns suitable mechanical properties for table tops and workbenches. Using this product as an artificial stone represents an innovation in the development of a new product and adds commercial value to local waste. This product is an excellent example of a circular economy for local producers who care about the environment, and it encourages the reduction of extraction of natural stone, such as granite and marble.

Due to the good chemical stability regarding lithium and cathode materials under high voltage, Li7La3Zr2O12 (LLZO) is considered as a promising electrolyte in all-solid-state Li-ion batteries. However, to enable stable long-term operation, knowledge of the mechanical boundary conditions is required. Since mechanical properties of the components and cells depend on the microstructure, the micro- and macro-mechanical properties of LLZO were investigated systemically via indentation tests and ring-on-ring bending (ROR) tests. Hence, fracture stress, elastic modulus, hardness and indentation fracture toughness of the material were characterized under different applied loads. Additionally, room-temperature subcritical crack growth effects were studied on the basis of loading rate-dependent ROR test derived data in order to assess potential reliability issues of LLZO components under application-relevant conditions. A strength–probability–lifetime plot is derived on the basis of these fracture stress data. Complementary optical and electron microscopic investigations were carried out. The Weibull modulus of LLZO is 6, and the stress should not exceed 21 MPa for a lifetime of 3 years to warrant a failure probability of 1%.

Preparation of high-performance carbon fibers from low-cost precursors, such as asphaltenes, is of great importance to the mass production of carbon fibers. In this investigation, asphaltenes from a solvent de-asphalting process were thermally pretreated at various temperatures to obtain asphaltene-based precursors. Thermal pretreatments, especially at higher temperatures up to 350 °C, produced much higher fiber winding speeds (750 m/min) and smaller as-spun fiber diameters (7–8 μm). A bimodal Weibull distribution of failure stress was found for carbon fibers derived from pretreated asphaltenes precursors. A higher Weibull modulus (m3 = 3.47) was observed at lower failure stresses, which is attributed to the presence of some uniformly distributed defects. A lower Weibull modulus (m4 = 0.67) was found at higher failure stresses, indicating the presence of clustered defects. Elemental analyzer, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to understand chemical and microstructure evolution of the pretreated asphaltenes and the derived fibers during various stages of fiber treatments.