Thickness Of Interaction Layer Research Articles

A Study of the Friction Stir Lap Welding of AA5052 and Polypropylene.

Friction stir lap welding (FSLW) remains a pioneering technique for creating hybrid joints between AA5052 aluminium alloy and polypropylene (PP), particularly with the metal-on-top configuration. Building upon previous research, this study introduces a tapered fluted pin tool design and investigates its effectiveness in the welding process. Our results, supported by ANOVA, chemical, and microstructural analyses, reiterate that the optimal welding parameters stand at a rotational speed of 1400 RPM and a traverse speed of 20 mm/min. This combination produces a joint tensile strength of 3.8 MPa, signifying 16.54% of the weaker material's inherent strength. Microstructural evaluations revealed a unique composite of aluminium chips intermeshed with PP, strengthened further by aluminium hooks. Crucially, mechanical interlocking plays a predominant role over chemical bonding in achieving this joint strength. The study underscores the absence of significant C-O-Al bonds, hinting at the PP degradation without the thermo-oxidation process. Additionally, joint strength was found to inversely correlate with the interaction layer's thickness. The findings fortify the promise of FSLW with the novel fluted pin design for enhancing joints between AA5052 and PP, emphasising the potential of mechanical interlocking as a principal factor in achieving high-quality welds.

Microstructure and microchemistry changes at U-10Mo fuel/AA6061 cladding interfaces with varying hot isostatic pressing conditions

Monolithic uranium - 10 wt.% molybdenum (U-10Mo) is a promising high-assay low-enriched uranium fuel system for nuclear reactors used in research, medical isotope production, and remote power applications. During manufacturing, an aluminum alloy (AA6061) cladding is bonded to the U-10Mo fuel plate via hot isostatic pressing, during which diffusion and fuel/cladding chemical interaction occurs at plate edges. The microstructure and microchemistry changes that occur at fuel/cladding interfaces are important to understand as a function of process parameters to develop a reliable fuel fabrication process and to meet the desired specifications. Here, microstructural and microchemical changes are studied using complementary electron microscopy and atom probe tomography for two manufactured fuel plates with varied hot isostatic pressing (HIP) parameters. Results highlight that modifying thermomechanical processing parameters significantly changes the interaction layer thickness between U-10Mo and AA6061 by an order of magnitude. In addition, the distribution and concentration of elements (i.e., Al, Si, Mg) from cladding to fuel are investigated.

The deformation model of the DCB-sample with elastoplastic properties

The loading of a strip with a crack-like defect according to mode I is considered. In contrast to the classical representation of a crack in the form of a mathematical section, the proposed model defines a crack as a physical cut with a characteristic linear size. The mental continuation of a physical cut in a solid forms an interaction layer (IL). It is important that the stress-strain state of the layer at a finite value of the linear parameter does not introduce a singularity into the crack model. The process of elastoplastic deformation with a constant layer length is considered. We obtained a simplified analytical solution to the problem of deformation of two elastic bodies connected by a thin layer with elastoplastic properties. The dependence of the displacement and stress fields on the length and thickness of the interaction layer has been found. It is shown that, under the classical plasticity condition, the range of variation of the external load leading to a purely elastic behavior is possible only for a finite layer thickness. As the layer thickness tends to zero, as in the Dugdale model, the plasticity region is formed at an arbitrarily small external load. For small layer thicknesses, a local plasticity criterion is proposed, by using which it is possible to distinguish the intervals of the external load variations associated with elastic and plastic deformations. The local plasticity condition, determined by the critical value of the energy product, makes it possible to reflect the stage of elastic deformation at an arbitrarily small finite thickness of the interaction layer. An asymptotic dependence of the external load on the IL thickness and the reduced length of the plastic zone is obtained. At the same time, the separation of the external load into elastic and plastic components is preserved. From the analysis of the experimental data, an estimate of the elastic limit of the energy product for the AV138 adhesive was obtained.

The Effect of Parameters on the Process of Making Objects with Rapid Prototyping Digital Light Processing Technology on the Bending Stress

The world is currently entering the era of the industrial revolution of 4.0. The era in which the occurrence of disruptive technology. The main purpose of this existence of the industrial revolution to create stability in the distribution of goods and necessities. Broadly speaking, there are some benefits that can be posed by the presence of the industrial revolution 4.0 is encouraging research, customization, and optimization. In addition, there are several challenges to be faced in the industrial revolution was the first IE 4.0 security, the second is the capital, and then a third that is employment, and the fourth is privacy. A method that can respond to these challenges is additive manufacturing using SLA-DLP 3D Printing. The making of objects utilizing CAD data that have been made in advance. This research aims to know the effect of object making process parameters with digital light processing rapid prototyping technology on bending stress. The parameters investigated is the layer thickness and the exposure time. Test specimens made of a material with liquid photopolymer resin refer to ASTM D 790 using SLA-DLP 3D Printer. Measurement results in data analysis using ANOVA design with type 2 factorial design model and level 1 factorial interactions assisted by software Design Expert trial version. The results of the ANOVA is known that factors significantly (α = 0.001), to effect of object making process parameters with digital light processing rapid prototyping technology on bending stress., that are the layer thickness=10%, exposure time=2%, interaction layer thickness and exposure time=87%.

A novel fed friction-stir (FFS) technology for nanocomposite joining

A novel solid-state manufacturing technology called as fed friction-stir (FFS) process was introduced based on the well-established friction-stir welding (FSW) for fabrication of metal–polymer nanocomposite by dissimilar joining, and implemented on a system of AA6082 aluminium alloy and poly-methyl-methacrylate (PMMA) polymer in the T-joint design. FFS technology was found very effective in strengthening the weld nugget and enhancing the dissimilar nanocomposite joining efficiency between aluminium and polymer with respect to FSW without reinforcing agent. Injection of Al2O3 nanoparticles with a high-concentration inside the lower region of weld nugget resulted in decreasing the cooling rate and thickness of interaction layer at the interface as well as a considerable increase in the tensile strength of nanocomposite joint up to ∼20% (60 MPa).

Model crack with a scalable linear parameter

The cracked body strain problem is considered in a linearly elastic formulation on the basis of the interaction layer (IL) concept for loading with opening mode or shear. The stress state in the IL is determined on the basis of the average-thickness characteristics of the stressed and strained state (SSS). The proposed problem formulation includes the linear parameter (LP). The wedge force-to-IL thickness relation is derived proceeding from the problem’s analytical solution to a beam approximation. It is shown that it is possible to use the energy product of the linear size and the increment in the layer’s specific free energy as the generic criterion of destruction. The established association of the specimen size with the critical force ensures is found out to ensure the independence of the critical force from the IL thickness to a desired degree of precision. The resulting and the conventional solution for a notch in the form of mathematical cut are compared to determine the assumptions on which Griffith’s criterion concurs with the EP criterion.

Investigation of diffusional interaction between P91 grade ferritic steel and Fe-15 wt.%B alloy and study of kinetics of boride formation at high temperature

In the present study, the feasibility of employing the indigenously developed ferroboron alloy (Fe-15 wt.%B) as an alternate neutron shield material in combination with 9Cr-based ferritic steel (P91) clad in future Indian fast breeder reactors (FBR), has been investigated from a metallurgical perspective. Towards this goal, a series of diffusion couple experiments have been conducted at three different temperatures namely, 600, 700 and 800 °C for time durations up to 5000 h. The thickness of interaction layer has been monitored using standard metallographic procedures. The experiments revealed that ferroboron/P91 combination exhibited a tendency to form complex intermetallic borides at the interface. The structural and microstructural characterization of the interface confirmed that the reaction layer consists predominantly of borides of Fe and Cr of type FeB, Fe2B, (Fe,Cr)2B and (Fe,Cr)B. The measured variation of interaction layer thickness as a function of time and temperature have been modelled in terms of diffusion mediated interaction. The growth kinetics of borided layer has followed the parabolic law at each temperature, and the apparent activation energy for boride layer formation is found to be of the order of 115 kJ mol−1. This indicates that the kinetics of boriding could be governed by diffusion of B into the P91 matrix. Based on the findings of present study, an extrapolative estimate of the clad attack thickness at 550 °C for 60 years of operating time has been made and it turns out to be 210 ± 15 μm, which is less than the clad thickness of FBR shielding subassembly (4 mm) [1]. Thus, this study confirms that at testing temperatures from 550 to 600 °C, the ferroboron/P91 steel combination can be safely employed for shielding subassembly applications in fast reactors.

Modeling a failure criterion for U–Mo/Al dispersion fuel

The breakaway swelling in U–Mo/Al dispersion fuel is known to be caused by large pore formation enhanced by interaction layer (IL) growth between fuel particles and Al matrix. In this study, a critical IL thickness was defined as a criterion for the formation of a large pore in U–Mo/Al dispersion fuel. Specifically, the critical IL thickness is given when two neighboring fuel particles come into contact with each other in the developed IL. The model was verified using the irradiation data from the RERTR tests and KOMO-4 test. The model application to full-sized sample irradiations such as IRISs, FUTURE, E-FUTURE, and AFIP-1 tests resulted in conservative predictions. The parametric study revealed that the fuel particle size and the homogeneity of the fuel particle distribution are influential for fuel performance.

Fission induced swelling of U–Mo/Al dispersion fuel

Fission-induced swelling of U–Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U–Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U–Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U–Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U–Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

Effects of heat treatment on U–Mo fuel foils with a zirconium diffusion barrier

A monolith fuel design based on U–Mo alloy has been selected as the fuel type for conversion of the United States’ high performance research reactors (HPRRs) from highly enriched uranium (HEU) to low-enriched uranium (LEU). In this fuel design, a thin layer of zirconium is used to eliminate the direct interaction between the U–Mo fuel meat and the aluminum-alloy cladding during irradiation. The co-rolling process used to bond the Zr barrier layer to the U–Mo foil during fabrication alters the microstructure of both the U–10Mo fuel meat and the U–Mo/Zr interface. This work studied the effects of post-rolling annealing treatment on the microstructure of the co-rolled U–Mo fuel meat and the U–Mo/Zr interaction layer. Microscopic characterization shows that the grain size of U–Mo fuel meat increases with the annealing temperature, as expected. The grain sizes were ∼9, ∼13, and ∼20μm for annealing temperature of 650, 750, and 850°C, respectively. No abnormal grain growth was observed. The U–Mo/Zr interaction-layer thickness increased with the annealing temperature with an Arrhenius constant for growth of 184kJ/mole, consistent with a previous diffusion-couple study. The interaction layer thickness was 3.2±0.5μm, 11.1±2.1μm, 27.1±0.9μm for annealing temperature of 650, 750, to 850°C, respectively. The homogeneity of Mo improves with post rolling annealing temperature and with U–Mo coupon homogenization. The phases in the Zr/U–Mo interaction layer produced by co-rolling, however, differ from those reported in the previous diffusion couple studies.

MODELING OF INTERACTION LAYER GROWTH BETWEEN U-Mo PARTICLES AND AN Al MATRIX

Interaction layer growth between U-Mo alloy fuel particles and Al in a dispersion fuel is a concern due to the volume expansion and other unfavorable irradiation behavior of the interaction product. To reduce interaction layer (IL) growth, a small amount of Si is added to the Al. As a result, IL growth is affected by the Si content in the Al matrix. In order to predict IL growth during fabrication and irradiation, empirical models were developed. For IL growth prediction during fabrication and any follow-on heating process before irradiation, out-of-pile heating test data were used to develop kinetic correlations. Two out-of-pile correlations, one for the pure Al matrix and the other for the Al matrix with Si addition, respectively, were developed, which are Arrhenius equations that include temperature and time. For IL growth predictions during irradiation, the out-of-pile correlations were modified to include a fission-rate term to consider fission enhanced diffusion, and multiplication factors to incorporate the Si addition effect and the effect of the Mo content. The in-pile correlation is applicable for a pure Al matrix and an Al matrix with the Si content up to 8 wt%, for fuel temperatures up to 200 ℃, and for Mo content in the range of 6 ? 10wt%. In order to cover these ranges, in-pile data were included in modeling from various tests, such as the US RERTR-4, -5, -6, -7 and -9 tests and Korea’s KOMO-4 test, that were designed to systematically examine the effects of the fission rate, temperature, Si content in Al matrix, and Mo content in U-Mo particles. A model converting the IL thickness to the IL volume fraction in the meat was also developed.

Determining the thermomechanical characteristics of the separation process

The crack growth condition was obtained in [1, 2] from energy considerations and holds for arbitrary nonlinearly elastic materials. This condition is reduced to determining the trajectory-independent transition from one of the shores of the mathematical cut to the other shore in the J-integral. The time when the J-integral attains the critical value corresponds to the initiation of crack motion. In the present paper, we consider the steady-state strip separation process starting from the fundamental thermodynamic relation. The strip material behavior is determined both at the stage of stable (in general, elastoplastic) loading and at the stage of Drucker unsdtable strain until the time at which the interaction between particles ceases. We single out a domain of unstable material strain, i.e., an interaction layer whose initial width is assumed to be a universal constant of the material [3]. The proposed approach permits expressing the material surface energy via the critical thermomechanical parameters (determined from the complete strain diagram) and the interaction layer thickness. We obtain expressions for the critical values of J-integrals. The critical values of J-integrals [4–6] corresponding to nonlinearly elastic and ideally plastic materials follow from general considerations. We have shown that the possibility of using J-integrals as elastoplastic separation criteria depends on the layer thickness of an irreversibly strained material. If the corresponding thickness is independent of the boundary conditions and the body geometry, then it is possible to use the value of the J-integral as a separation criterion; this corresponds to the Irwin-Orowan quasibrittle fracture approach.