The effect of 3D printing parameters on parts hardness has been studied and optimized. Al-5356 alloy parts are manufactured using Cold Metal Transfer (CMT) technique. Torch traveling speed, gas flow rate, and current intensity are the essential CMT factors used. The main objective of the following study is to find and localize the hardness distribution from the bottom to top of CMTed parts and optimize the parameters in order to find out factors that give high hardness. To this end, the following factors have been chosen according to the Taguchi method of an orthogonal L9 design test. The latter method reveals highest optimization corresponds to the top zone, and the low one returns to the bottom zone. Whereas, zones between the top and the bottom have close values of optimized hardness. Besides the Taguchi method, the analysis of variance (ANOVA) was applied to statistically identify the effects of factors and model validation. The results found show that all factors have a significant impact on hardness. SEM images and microstructural studies confirmed the results of the hardness investigation using the Taguchi method. i.e., the top zone part contains more porosity than the bottom. The existence of the latter affects the hardness. In addition, microstructural investigation shows that the small grain size is located at the bottom, in contrast to the top due to the rapid solidification of aluminium and different heat distribution.
One-dimensional photonic crystals (1D-PhCs) have attracted considerable attention owing to their ability to manipulate electromagnetic wave propagation through photonic bandgap (PBG) formation. In conventional structures, the refractive indices of the constituent layers are assumed constant, which limits the flexibility in tailoring their optical response. In this study, a novel 1D-PhC incorporating a layer-to-layer graded refractive index profile and a central defect cavity is proposed and theoretically investigated. The structure consists of alternating silicon dioxide (SiO2) layers with a fixed refractive index and silicon (Si) layers, whose refractive indices vary discretely according to the layer-to-layer refractive-index grading parameter, Δn. Moreover, a defect layer has been introduced at the center of the structure to generate a localized resonant mode within the PBG. The optical properties of the described structure were analyzed using the Transfer Matrix Method (TMM). The results showed that as Δn increased significantly, the PBG expanded from 393.7 to 747.4 nm, accompanied by a red shift of the defect resonance wavelength from 737.8 to 816.8 nm. However, the resonance line width decreased considerably, which enhanced the quality factor from 10³ to 5.1 × 10⁴. It was found that layer-to-layer refractive index grading could be an effective approach for PBG engineering and defect mode control, making the proposed structure a promising candidate for optical filters, resonators, and high-performance photonic devices.
Manganese is an indispensable strategic resource in the steel, chemical, electronics, and new energy sectors. As the primary solid waste generated during the production of electrolytic manganese metal, electrolytic manganese slag accumulates in massive quantities, yet its comprehensive utilization rate remains below 10 %. This slag is rich in characteristic pollutants such as high concentrations of manganese ions (Mn²⁺), ammonia nitrogen (NH₄⁺-N), and sulfates (SO₄²⁻), posing a severe challenge to the ecological environment. In recent years, technologies for the safe disposal of electrolytic manganese slag have primarily included water washing, high-temperature solidification, and chemical solidification; these methods can effectively reduce its leaching toxicity. In terms of resource recovery, research and applications have expanded into multiple directions, such as the production of construction materials (cement, concrete, unburned bricks, and roadbed materials), the development of agricultural fertilizers, the recovery of valuable elements, and the synthesis of high-value-added products.
There are many approaches to predict the average pressure acting in the cutting zone, and these are usually based on specific cutting force and the cutting resistance. Common theme for these modelling approaches is to use chip thickness to describe the uncut chip. These models are usually based on process parameters such as the depth of cut ap, radial engagement ae and feed per tooth fz. The purpose of this paper is to investigate the underlying process parameters affecting the main cutting force in milling operations using the Full Factorial Design model. For this study, single-tooth climb milling with indexable carbide inserts in medium carbon steel C45E, were selected. The design, and experiment, and analysis were performed using Modde Pro. During the test, the main cutting force was measured with a dynamometer and compared with the results from the FFD model. These results revealed that the inclusion of the interaction of parameters in the model was important for the model accuracy. As expected, it also shows that any increase of ae, ap, and fz will increase the main cutting force and therefore all three parameters should be included in a DoE, when modelling main cutting force in milling. In conclusion, a statistical approach can be used to calculate the main cutting force, complementing the traditional models that are based on cutting resistance and chip thickness.
This study presents the development and evaluation of optimized pigment paste formulations for UV-curable nail coatings based on seven organic pigments. The influence of the monomer-oligomer ratio, pigment loading, and dispersants was examined using planetary mixing, high-speed dispersion, and three-roll milling. Paste quality was assessed through rheological measurements, grind gauge analysis, and opacity evaluation. The results demonstrate that dispersion behavior is strongly pigment-dependent and requires tailored formulation strategies. Stable, cream-like pastes suitable for automated handling were obtained by balancing pigment concentration with base viscosity and dispesrsant performance. Three-roll milling at 20/10 μm gaps and 160 rpm produced only minimal opacity changes (ΔOP = 0.27%), indicating that organic pigments disperse effectively even without intensive mechanical milling. The results establish the first comparative formulation framework for organic pigments tailored to automated production of UV-curable nail coatings. The proposed approach supports the development of stable dispersions with controlled rheological and optical properties enabling efficient and scalable production of coatings for industrial applications.
