Fused Deposition Modeling (FDM), the preferred additive manufacturing technology used for creating plastic-based parts, due to its affordability and simplicity of use. A well-known material used in FDM is Polylactic acid (PLA); however, its mechanical properties limit its use as a functional part for many applications. This research investigates the effect Copper-reinforcement has on PLA material's ultimate tensile strength (UTS) during production with a FDM process. The max tensile strength measured during this study was produced using a combination of low layer thickness (0.14 mm), high infill (90%), and high printing speed (100 mm/s). The wall thickness had a point of maximum tensile strength which was found at approximately 1.2 mm before strength began to decrease. Surface finish results were achieved with a combination of 0.14 mm layer thickness, 95 mm/s printing speed, 85% infill, and 1.0 mm wall thickness, and deviations from these settings led to increased roughness due to thermal and structural factors. Multi-objective evolutionary algorithm-based optimization MOEA/D method produced a combined "knee" point for tensile strength that was greater than all the highest experimental tensile strength measures while maintaining surface roughness identical to established through experimental means, demonstrating the effectiveness of multi-objective FDM parameter optimization utilizing it.

In this study, Carbon, Glass, and Aramid fiber reinforced composite and their hybridized forms were fabricated using five different stacking sequences of the fabrics. Using the Vacuum Assisted Resin Transfer Molding (VARTM) procedure, epoxy resin was injected into these fabrics and allowed to cure at room temperature. From these five stacking sequences, a standard specimen with four different orientations viz. 0/90°, 15/75°, 30/60°, 45/-45° orientations were obtained using the Abrasive Water Jet Machining(AWJM) Process. The influence of stacking order and fiber orientation on tensile and flexural properties of composite was investigated. From the result of tensile testing, the highest and lowest tensile strength values were observed for neat carbon fiber reinforced composite at 0/90° orientation and at 45/-45° orientation respectively. The highest flexural strength was achieved in a hybrid combination of two layers of carbon, glass and aramid fabric for 0/90° whereas the lowest flexural strength was found in glass reinforced composite for the 45/-45° orientation.

The number of types of wire welding that circulate on the market and the development of welding technology, especially related to current welding, create a lack of information related to the quality of welding results for several types of materials. This can cause the strength of the welding connection to not be maximized. Therefore, this study aims to optimize the use of three types of wire welding and three current welding on the strength of the welding connection in two types of material testing using the response surface methodology. Box-Behnken, coupled with the RSM and the desirability function, was used to optimize the strength of the welding connection of the wire types (RD-46, LB-52, and RB-26), and current welding (100, 130, and 160 A) against two types of material testing (IWF-150 and ASTM-A517-G70). The strength of the welding connection observed in response included the tensile strength, Charpy impact-absorbed energy, hardness values in the welding metal and the hardness values in the main metal. Optimization of the strength of the welding connection in this study recommends the application of wire types RB-26, current welding of 100 A, and ASTM-A517-G70 material testing with the highest desirability value of 71.6%. Optimization of tensile strength, Charpy impact-absorbed energy, hardness values in welding metal, and hardness values in main metal by applying this parameter are 575.64 MPa, 110.69 J, 216.75 (HV10) and 126.6 (HV10), respectively. The results proved that an appropriate welding connection strength could be achieved using wire welding types and current welding in material testing.

The application of Fused Deposition Modeling (FDM) is restricted due to limited information about the mechanical properties of printed parts. Therefore, it is required to determine the mechanical properties of the FDM properties to avail the full benefit of the FDM process. In the present study, Classic Laminate Theory (CLT) has been employed at the different configurations of layer thickness and raster width. The required elastic constant of material for CLT has been experimentally obtained through FDM printed Polylactic Acid (PLA) unidirectional specimens at 0°, 45° and 90° for different combinations of layer height and raster width. For these different combinations of layer height and raster width, constitutive models were developed to predict the tensile properties of the PLA parts. Tensile strength of the FDM printed bi-directional specimens has been experimentally obtained to validate the proposed CLT model results. The experimental tensile strength data is in good agreement with the data predicted by the proposed CLT model. Higher tensile strength and modulus were achieved with 0° raster angle compared to 90° raster angle. In the case of a bi-directional printed specimen, higher tensile strength was obtained with 45°/-45° raster angle followed by 30°/-60° and 0°/90° raster angle.

The efficacy of stainless-steel micro-particles on friction stir processed aluminium-based matrix composite (ABMC) was studied using tribological, mechanical and structural analysis tools. The stainless-steel powder (17-4PH) of average size 45 – 90 µm was used as the reinforcement particle. The parametric values employed during the fabrication of ABMC- AA7075-T651/17-4PH were the rotational speed of 1500 rpm and travel speed of 20 mm/min while the plunge depth and tilt angles used were respectively 0.3 mm and 3 degrees. Tribological study was carried out under the influence of dry sliding condition with varying loads of 20 N and 50 N using tribometer while the scanning electron microscope (SEM) was used to capture the wear track. Structural analysis was examined with the aid of x-ray diffraction (XRD). The tensile strengths of the fabricated ABMC were also tested and the fracture surfaces were studied using SEM analysis. The results from the study revealed that at higher loading of 50 N, the wear performance was significantly improved for the fabricated aluminium composite- AA7075-T651/17-4PH when compare with lower loading of 20 N. The tensile properties for the ABMC were also improved under the influence of the stainless steel microparticles. There was structural improvement in ABMC wherein the value for crystallite size was lowest while micro-strain, dislocation density, as well as full width at half maximum (FWHM), had the highest values over the FSPed AA7075-T651 and the parent material. The examined fractured surface of the fabricated composite was dominated with fine, network and equiaxed dimples with cup and cone attributes confirming superb interfacial bonding and that the failure mode was ductile.

Foam made panels as efficient building elements are becoming a major role player in modular construction with a variety of applications worldwide. However, construction accuracy, technology, and method can have serious effects on the panels’ behavior. In this study, using a unique pneumatic pressure testing rig, bending tests are conducted on the two types of rigid polyurethane panels. The panels are categorized based on the existence of construction cold joints (seams) as S (Seamless) type and TS (Transverse Seams) type. The S type panels are tested under monotonic uniform loading with a maximum nominal pressure of about 1 atm as the witness specimens. The TS panels are tested under both monotonic and cyclic uniform loading, and the deflections-pressure behavior obtained. The results show that S panels could resist up to 0.77 atm under monotonic uniform loading, while the minimum tensile strength of the foam is 13 MPa. In addition, panels with transverse seams collapsed under monotonic and cyclic loads at an average of 0.46 atm and 0.33 atm respectively but at the same position, located on the seamed section, which represent the same failure mode. Based on the results, the seamed section exhibited a maximum tensile strength of about 33.1% of an intact section under monotonic loading; and 27.9% lower results under cyclic loading.

Aluminium alloy AlMg4.5Mn has got comprehensive acceptance in the manufacturing of light weight frames, marine structures which require high strength and worthy corrosion revulsion. The present investigation work focuses on friction stir welding process in which influences of operating parameters have been studied on friction stir welded butt joints. The FSWed joints specimens have been produced by experimentation at three levels of tool traverse speed and tool rotational speed keeping input force and tool tilt angle constant. Mechanical properties and microstructure of welded joints have been investigated in the present study. Change in the microstructure at different zones which transforms the mechanical properties of welded joints was due to the asymmetrical flow of material and thermal cycles around the pin. The second phase beta grains are formed as the very high temperature reached due to input parameters combinations. Traverse speed (TS) and tool rotational speed (TRS) are taken in a range of 16-40 mm/min and 500-1400 rpm, respectively. The best combination of parameters results in higher tensile strength which is well supported by the micro-hardness curve and the compact grains microstructure profile. Microstructure at different points and physical properties exhibited by the welded joint are well brought into line to summarize the effects of different parameters.

In this paper, butt joining of Al5083 to commercially pure copper is investigated by friction stir welding method. The effects of transverse welding speed of the tool on the mechanical properties and microstructure of the joint were studied, experimentally. By examining different circumstances, changes in the joint strength were studied and optimized in term of transverse speed. Based on the obtained results, welding speed can improve or reduce the joint strength and an optimum value can be found for the welding speed. Welded Joint that was conducted at the rotation speed of 800 RPM and tool traverse speed of 60 mm min?1 had the highest tensile strength (i.e. about 98% of the weak base metal). Intermetallic compounds were formed in the stir zone and XRD results indicated that Al4Cu9 and Al2Cu were the intermetallic compounds in the stir zone. Micro-cracks formed around the intimatelic particles were observed in the section of joint.