Effect of FW conditions on mechanical and microstructural characteristic of AA6061/SiC/Graphite hybrid composites joint by empirical relationship

Friction welded AA6061 matrix hybrid composite joints were investigated to understand the process effect on the metallurgical properties with the aid of empirical relationships. SiC of 10 % with the standard particle size of 25 µm and 5 % graphite with the particle size of 30 µm were added into the AA6061 matrix. The investigation has 20 sets of experiments as per the matrix designed. Each process condition, namely rotation speed (N), upset load (F), and upset time (T), as well as their impact on joint properties, were investigated individually, with the estimated tensile strength correlated to their corresponding metallographic properties. The observation of this study concludes that the disparity in grain size is mainly affected by the availability of heat sources and the plasticized material during the friction stage and it is highly influenced by rotation speed. Furthermore, the lower level parameters produce the defective joint while the higher-level parameters are attributed to ejecting the extensive amount of hot material from the joint interface. Finer reduction in grain size of 1.5 µm and ample plasticized material consolidation at the optimized welding conditions of 1600 rpm rotation speed, 3.5 kN upset load, and 4 s upset time were attributed to achieving the maximum tensile strength of 167 MPa.

Reactive Air Brazing of TiAl Alloy Using Ag-CuO: Microstructure and Joint Properties

TiAl alloy was successfully brazed with Ag-CuO filler in air atmosphere under simple technical conditions. The wettability of a series of Ag-CuO fillers on TiAl was analyzed. Ag-2mol%CuO filler possessed good wetting behavior on TiAl alloy. The microstructure and mechanical properties of the brazed joints were investigated. Oxide layers can be found on both sides, which can be divided into external TiO2-rich layer and internal Al2O3-rich layer. The maximum shear strength of the joint was obtained at 1020 °C holding for 20 min.

Effect of dwelling time and plunge depth on the joint properties of the dissimilar friction stir spot welded aluminum and steel

Sound joints of a far apart property, pure aluminum and mild steel, dissimilar materials were obtained by friction stir spot welding (FSSW) solid state joining process. Sheets of 2 mm thickness were overlapped and fixed with a fixture device then welded. Welding parameters that produced the sound joint were identified. Joints microstructure and mechanical properties were investigated. A microstructural investigation has revealed a creation of mechanical interlocking and discontinuous formation of the intermetallic compounds found at the interface. The intermetallic compound (IMC) layer thickness ranged from 6 μm to 17 μm with the optimum condition specimen, 800 rpm and 5 Sec dwell time. Tensile–shear test showed that failure load has increased with increasing tool plunge depth and rotational speed. After the optimum value of rotational speed, the shear failure load decreased. The maximum shear failure load of 2.15 KN attained at 800 rpm and 2.4 mm plunge depth.

Experimental investigation of modified co-curing process for carbon fiber/epoxy-laminates

In this study, thermoset-based carbon fiber-reinforced polymer structures manufactured by the so-called modified co-curing process are analyzed and compared to well-established co-curing and co-bonding. The modified co-curing process allows manufacturing geometrically complex parts without traditional core technologies by producing laminates from a un-cured half and a pre-cured half in contrast to using two un-cured halves (co-curing) or a fully cured half plus an un-cured half (co-bonding). The interlaminar fracture toughness under Mode I loading, [Formula: see text], was determined in double cantilever beam (DCB) tests. [Formula: see text] displays a correlation of the degree of cure and the joint properties, with the co-curing laminates having 11% and 33% higher fracture toughness than the modified co-curing configurations. However, modified co-curing in all cases results is superior or equal to co-bonding. To assess the influence of surface properties for the bonding quality, different peel plies were compared with respect to the resulting joint properties. The results with up to 50% loss in [Formula: see text] values indicate the high importance of appropriate surface preparation. Subsequent tests also show that the negative influence of the peel ply on the joint properties can be reversed by abrasive surface treatment. It was found that at higher degrees of partial curing before co-curing, crack growth increasingly occurs in the interface of the bonded laminates. Therefore, the properties of the surface before joining were analyzed and modified to assess its relevance for the bonding properties and the potential for improvement.

Interpolation Methods Applied on Biomolecules and Condensed Matter Brownian Motion

Biophysical and condensed matter systems connection is of great importance nowadays due to the need for a new approach in microelectronic biodevices, biocomputers or biochips advanced development. Considering that the living and nonliving systems’ submicroparticles are identical, we can establish the biunivocally correspondent relation between these two particle systems, as a biomimetic correlation based on Brownian motion fractal nature similarities, as the integrative property. In our research, we used the experimental results of bacterial motion under the influence of energetic impulses, like music, and also some biomolecule motion data. Our goal is to define the relation between biophysical and physical particle systems, by introducing mathematical analytical forms and applying Brownian motion fractal nature characterization and fractal interpolation. This work is an advanced research in the field of new solutions for high-level microelectronic integrations, which include submicrobiosystems like part of even organic microelectronic considerations, together with some physical systems of particles in solid-state solutions as a nonorganic part. Our research is based on Brownian motion minimal joint properties within the integrated biophysical systems in the wholeness of nature.