Effects of artificial aging on storage substances and physiological metabolism of maize (Zea Mays L.)

Effect of artificial aging on the translucency of monolithic zirconia materials sintered at different temperatures

In this paper, the author deals with the resistance of light polymer foils based on microporous functional film, used as additional waterproofing layers of pitched roofs. He exposes these foils to the effects of natural ageing and the effects of artificial ageing according to the methodology of the European test standard. Subsequently, it verifies the tensile properties of the exposed foils and compares the effects of natural and artificial ageing in order to determine the possible cause of premature degradation of these materials, which often occurs in practice. He concludes that the cause of this degradation is not excessive leniency of testing standards, but the insufficient quality of materials supplied to the European market.

The present work focuses on the effect of multistage solution heat treatment (MSHT) and artificial aging on two-stage stir-cast LM4 + TiB2 (1, 2, and 3 wt.%) composites on the mechanical properties as compared to as-cast and single-stage solution heat-treated (SSHT) composites. Two novel tests, viz. the confirmation hardness test and the chemical analysis test, were performed to ensure the soundness of the casting and uniform distribution of TiB2 within the matrix. Samples subjected to MSHT + aging at 100–200 °C displayed the highest hardness and UTS values compared to as-cast and SSHT + aging at 100–200 °C samples. Compared to as-cast alloy, peak-aged samples of 1–3 wt.% (MSHT + aging at 100 °C), hardness values improved from 107–150%, and UTS values improved from 47–68%. The presence of metastable phases (θ′-Al2Cu and θ″-Al3Cu) and of hard TiB2 particles are the reason for the improvement in the properties. Peak aged LM4 + 3 wt.% TiB2 composite displayed the highest hardness of 175 VHN and UTS of 251 MPa. Fracture analysis of the LM4 alloy showed dimple rupture, and its composites revealed quasi-cleavage fracture. Based on the overall results, the inclusion of TiB2, MSHT, and artificial aging treatment on the LM4 alloy significantly influenced the composites’ mechanical properties.

Marginal adaptation of CAD/CAM zirconia-based crown during fabrication steps

UHMWPE crosslinked using Gamma radiation is believed to have improved wear properties, and this has been extensively studied during the past 10 years. Mechanical properties, oxidation, and wear properties of UHMWPE materials subjected to various thermal treatments have been investigated immediately after irradiation as well as after several years of aging. Nevertheless, the relationship between all these parameters is not yet fully understood. The aim of this study was to investigate the relationship between the thermal treatments that could be applied to irradiated UHMWPE [lower (gamma 60) or higher (gamma 150) than 140 degrees C, the melting temperature of the polymer] and the mechanical properties, the oxidation and the fracture behavior of the material. The effect of artificial aging on these properties was also investigated. This study concludes that immediately after the annealing, the mechanical properties (UTS and epsilon) of the irradiated and annealed material are improved compared with those of nonirradiated material. Although nonirradiated material has higher fracture toughness than irradiated and annealed materials, the materials break according to the same mechanism of fracture. After aging, no changes could be observed in any of the measured properties for nonirradiated material. On the other hand, important changes could be seen in both irradiated and annealed material after aging. Both UTS and epsilon decreased, much more so in the case of gamma 60. Furthermore, the aging induced a subsurface peak of oxidation in both irradiated and annealed materials, twice as intense for gamma 60 than for gamma 150. The mechanism of fracture of these materials changed drastically after aging, probably due to the presence of the oxidation peak, which seems to occur at a location where cracks initiate easily compared with the nonoxidized bulk of the material. In the case of gamma 60, it seems clear that a correlation between mechanical property, oxidation, and fracture mechanism exists. Such a relationship could not be found for gamma 150.

Effect of artificial aging on the Cu-Mg co-clustering and mechanical behavior in a pre-strained Al-Cu-Mg alloy

Marginal adaptation of three different zirconium dioxide three-unit fixed dental prostheses

The primary objective of this study is to determine the most effective solution treatment and aging temperature for AA2024 aluminum alloy to achieve superior mechanical properties. In this research, a Severe Plastic Deformation (SPD) method known as Multi-Directional Forging (MDF), which is one of the useful methods for creating Ultra-Fine Grained (UFG) microstructure, was employed on AA2024. Due to the limited studies on the effects of artificial aging on this alloy in its supersaturated state following the MDF process, the alloy was subjected to solution treatments at 480°C, 500°C, and 520°C for 1h, followed by immediate MDF. Aging was then performed at 100°C, 140°C, 190°C, 240°C, and 290°C for 1h each, to achieve artificial aging. To investigate the microstructure and precipitate conditions, Optical Microscopy (OM) and Field Emission Scanning Electron Microscopy (FE-SEM) were used to analyze the cross-sectional surfaces of the samples. Mechanical properties were evaluated through hardness and compression tests. The study reveals that the sample solution-treated at 520°C exhibited the highest hardness and yield stress compared to those treated at 480°C and 500°C. The hardness of MDF samples increased from 82 HV to 165 HV as the aging temperature rose to 140°C, where the highest hardness, flow stress, and yield strength were observed. At 190°C for aging temperature, full recrystallization occurred, and at 240°C and 290°C, grain growth was observed, leading to a decrease in hardness, 128 HV and 97 HV, and yield strength, 505MPa and 386MPa, respectively. The results demonstrate that a solution treatment at 520°C followed by artificial aging at 140°C produces the best mechanical properties and microstructural characteristics in the AA2024 alloy, achieving the flow stress of 791MPa and yield stress of 621MPa.

The aim of the research was to modify the surface of construction textiles by means of the use of thin silver oxide films, investigate the structure and optical and mechanical properties, and determine the structure, optical and mechanical properties of the aged composites. Thin films of silver oxide (Ag2O) were synthesized on a flexible PET/PVC construction textile (CT); the structural, optical, and physical properties, as well as the effect of artificial aging on these properties, were investigated. The SILAR method (successive ionic layer adsorption and reaction) was used to synthesize thin Ag2O films on the CT surface. Before the thin films were deposited, the CT surface was mechanically roughened and pretreated with acidic and alkaline solutions at an elevated temperature. XRD analysis showed that the deposited films were a polycrystalline mixed phase material consisting of Ag2O, AgO, and metallic Ag. Diffuse reflectance spectra in the ultraviolet and visible ranges (UV-Vis) were used to study the optical properties of the deposited thin films. The synthesized Ag2O/CT composites were direct-gap semiconductors (the optical band gap (Eg) was 0.89 ± 0.02 eV). Eg and refractive indices (n) increased as the aging tests were carried out. Higher Eg and n meant that the composites were a good material for optoelectronic applications. The results showed that, after modification, the structural properties and tear strength of the PET/PVC fabric remained the same while the tensile strength decreased. The same tendencies remained after artificial aging.

Effect of artificial aging on the mechanical performance of (Al-Cu) 2024 and (Al-Cu-Li) 2198 aluminum alloys

Effect of artificial ageing on microstructural behaviour of friction stir welded AA2014 aluminium alloy joints

Impact mechanical behaviour of Al–7Si–Mg (A357) cast aluminum alloy. The effect of artificial aging

Adhesive joints in glass structures: effects of various materials in the connection, thickness of the adhesive layer, and ageing

The effects of aging on machinability of 6061 aluminium alloy

Effect of artificial aging on optical properties and crystalline structure of high-translucency zirconia.