INFLUENCE OF WIRE-EDM PARAMETERS ON SURFACE CHARACTERISTICS OF SUPERALLOY MONEL 400

Progressive development in the industrial field leads to the increasing demand for superalloys with enhanced mechanical properties, such as toughness, hardness, ductility, damping strength, tensile strength and improved surface finish. Monel 400, one of such superalloys, with the majority of its application in aerospace and marine fields demands a good super finish. There arises the need for some nonconventional processes like WEDM. This process is more effective to obtain complex shapes to close tolerance. This research focuses on clear understanding of the machining strategies with proper parametric combinations to achieve an improved surface finish, subsequently reducing the time and expense involved in the superfinishing procedure. The surface qualities of the selected samples are validated with the help of roughness profile and topography images. This study has proven that the increasing input current and wire feed rate (WFR) consistently decreases the surface roughness (SR; [Formula: see text] of the specimen. This paper also explains the effect of topographic parameters and microstructure over the resulting SR. In addition, the consistent contribution of WFR and input current toward the lower SR is established. The relationship between morphological behavior and parametric deviations is evaluated. A significant correlation found to exist between the rate of wire feed and the height parameters of SR such as [Formula: see text], [Formula: see text], etc.

Optimization of machining parameters in drilling hybrid sisal-cotton fiber reinforced polyester composites

<abstract> <p>Machining natural fiber reinforced polymer composite materials is one of most challenging tasks due to the material's anisotropic property, non-homogeneous structure and abrasive nature of fibers. Commonly, conventional machining of composites leads to delamination, inter-laminar cracks, fiber pull out, poor surface finish and wear of cutting tool. However, these challenges can be significantly reduced by using proper machining conditions. Thus, this research aims at optimizing machining parameters in drilling hybrid sisal-cotton fibers reinforced polyester composite for better machining performance characteristics namely better hole roundness accuracy and surface finish using Taguchi method. The effect of machining parameters including spindle speed, feed rate and drill diameter on drill hole accuracy (roundness error) and surface-roughness of the hybrid composite are evaluated. Series of experiments based on Taguchi's L₁₆ orthogonal array were performed using different ranges of machining parameters namely spindle speed (600,900, 1200, 1600 rpm), feed rate (10, 15, 20, 25 mm/min) and drill diameter (6, 7, 8, 10 mm). Hole roundness error and surface-roughness are determined using ABC digital caliper and Zeta 20 profilometer, respectively. Optimum machining condition for drilling hybrid composite material (speed: 1600 rpm, feed rate: 25 mm/min and drill diameter: 6 mm) is determined, and the results are verified by conducting confirmation test which proves that the results are reliable.</p> </abstract>

Compression strength-focused properties of wood composites induced by density

Compression strength-focused properties of wood composites induced by density. The aim of this study was to analyse the contractual compression strength and modulus of elasticity under compression of ten commercially available wood composites of various thickness, density, structure and surface finish. Density and density profiles have also been performed. The tests showed that there is no significant dependence of the compression strength and MOEC on the density of composites.

Late Medieval complexes of the forest-steppe and sub-taiga Trans-Urals (based on materials from the settlement of Stary Pogost)

The paper concerns the results of the archaeological investigation of the Late Medieval sites in the forest-steppe and sub-taiga regions of Trans-Urals (Western Siberia). With the example of the fortress of Stary Pogost, and using the materials on all studied Late Medieval sites of the region (the hillforts of Yelyak-Alyp, Maloye Bakalskoye, Chingi-Tura, Isker, Kuchum-gora, Ivanovskoye, Dolgovskoye 1, the sanctuary of Tsingalinskoye), the main aspects of the material culture of the population of the 14th–16th centuries have been reconstructed. The building structures are represented by above-ground or slightly sunken permanent buildings with pise-walled hearths. In the cultural level, ashy spots, cumulations of fish-scale, and bones of fish and animals were recorded. The sea-sonal occupancy of most of the settlements, thin cultural layer, small quantity or complete absence of ceramics complicate distinguishing of the Late-Medieval complexes from the full array of Medieval monuments of the forest-steppe and sub-taiga Trans-Urals. A statistical analysis of the ceramics collections from all Late Medieval sites of the Trans-Urals was carried out. Four main types of the ware were identified. By correlation with contemporaneous collections of the Middle Irtysh, local specifics of the ceramics of the studied region were determined. The small amount of the stoneware was noted. The decline of the ceramics manufacture reflected in the composition of the clay dough, surface finish, and shape of the vessels, and it was manifested by poor ornamentation or complete absence of décor. One type of the ware – large cauldron-shaped vessels with thick vertical or slightly inside-bent walls, flattened bottom, and poor ornamentation – was recorded only in the territory of the forest-steppe and sub-taiga Trans-Urals, as well as in the Ishym River area. This indicates its earlier chronological position (13th–14th cc. A.D.) and association with the population of the emerging Siberian Tatars. A widespread became the ware made from organic materials – wood and bark, as well as imported ware, including metallic items.

Study of the heat transfer and analysis of the surface characteristics of robot spray painting by using Taguchi method and ANOVA analysis

In this investigative research work, the surface characteristics of normal paint and multiwall carbon nanotube (MWCNT) paint-coated substrates are studied. The experiments are conducted using ABB IRB 1410 Robot and the end effector of the robot is retrofitted with a high-volume low-pressure atomizer paint spray gun. The nanopaint is prepared by ultrasonication by placing 1 gram of MWCNT in a polyurethane commercial base paint (500 ml). Taguchi design of experiments is used to identify the most efficient use of procedure parameters using the L9 orthogonal array table. Heat transfer of the substrate is found by temperature measurements of the convective heat transfer through extended surfaces. Surface morphology is studied by scanning electron microscope and upright microscopy. Analysis of variance technique is used to find the most influencing input parameters and contribution of values to maximizing surface finish and minimizing the heat transfer effect. The study shows that there is an enhancement in surface finish and minimization of heat transfer in the nanopaint coated substrate when compared with normal paint application using the ABB robot.

Process Capability Assessment Using Vision System

Surface roughness assessment would help in predicting a component’s functionality. This clearly shows the significance of measuring the surface roughness of machined components. Thus, each machined component, depending upon its intended function, requires a certain surface finish. To predict the surface roughness of a machined component, a detailed understanding of the machining parameters is essential. This is because, surface roughness generated on a component, depends upon machining parameters speed, feed, and depth of cut. A stable manufacturing process gives a consistent surface finish on all the manufactured components. Thus, only by having a stable process, consistent quality of manufactured products is possible. The capability of the machine is defined as the capability of the machine to carry out the set process efficiently and effectively to produce parts as per the specification limits. Machining parameters, tools, coolant flow rate, etc. An effort has been made in this research work, to show how by measuring surface roughness of machined components process capability can be assessed. Thus, the method is a novel technique of assessing the process capability of a given process. A capable process would help a manufacturing company in meeting customer expectations. The proposed method is of non-contact type, quick, and industry-friendly.

Influence of Flux and Related Factors on Intermetallic Layer Growth within SAC305 Solder Joints

Flux contained in solder paste significantly affects the process of solder joint creation during reflow soldering, including the creation of an intermetallic layer (IML). This work investigates the dependence of intermetallic layer thickness on ROL0/ROL1 flux classification, glossy or matt solder mask, and OSP/HASL/ENIG soldering pad surface finish. Two original SAC305 solder pastes differing only in the used flux were chosen for the experiment. The influence of multiple reflows was also observed. The intermetallic layer thicknesses were obtained by the image analysis of micro-section images. The flux type proved to have a significant impact on the intermetallic layer thickness. The solder paste with ROL1 caused an increase in IML thickness by up to 40% in comparison to an identical paste with ROL0 flux. Furthermore, doubling the roughness of the solder mask has increased the resulting IML thickness by 37% at HASL surface finish and by an average of 22%.

Effect of sphere configurated particle damper on tribological properties during boring of hardened steel

Tool vibration is the most unfavourable element in the boring operation, as it contributes to poor surface finish, excessive tool wear, and progressive cutting force. Tool vibration mainly occurs due to the overhanging length of the boring tool and to overcome this factor an appropriate mechanism has to be established which helps to increase the production and quality of the product in manufacturing sector. An impact particle damper with variable material spheres, sphere diameter, and sphere location in a boring tool is fabricated in this work. A 27 run experiments were conducted to find the effect of impact particle damping on tribological properties during boring process. The results shows that impact particle damper increases the rigidity of the tool holder which enhances the tribological properties. The sphere in the boring tool will collide with one another thereby suppressing the tool vibration efficiently.

Effect of Ni(P) Layer Thickness on Interface Reaction and Reliability of Ultrathin ENEPIG Surface Finish

Electroless Ni(P)/electroless Pd/immersion Au (ENEPIG) is a common surface finish in electronic packaging, while the Ni(P) layer increases the impedance of solder joints and leads to signal quality degradation in high-frequency circuits. Reducing the thickness of the Ni(P) layer can balance the high impedance and weldability. In this paper, the interfacial reaction process between ultrathin ENEPIG substrates with different Ni layer thicknesses (0.112 and 0.185 μm) and Sn–3.0Ag–0.5Cu (SAC305) solder during reflow and aging was studied. The bonding ability and reliability of solder joints with different surface finishes were evaluated based on solder ball shear test, drop test and temperature cycle test (TCT), and the failure mechanism was analyzed from the perspective of intermetallic compound (IMC) interface growth. The results showed that the Ni–Sn–P layer generated by ultrathin ENEPIG can inhibit the growth of brittle IMC so that the solder joints maintain high shear strength. Ultrathin ENEPIG with a Ni layer thickness of 0.185 μm had no failure cracks under thermal cycling and drop impact, which can meet actual reliability standards. Therefore, ultrathin ENEPIG has broad prospects and important significance in the field of high-frequency chip substrate design and manufacturing.