This study determined the optimal sintering parameters for tungsten carbide–cobalt cutting inserts produced by spark plasma sintering (SPS) to achieve a balanced combination of structural and mechanical properties for cutting tool applications. Sintering experiments were conducted using a GeniCore U-FAST GC vacuum SPS system. Sintering experiments were conducted using a GeniCore U-FAST GC vacuum SPS unit. A factorial design was applied, varying sintering temperature (1250–1500 °C), applied force (0.4–0.6 kN), dwell time (5–10 min), and pulse current (4000–4800 A). The results indicate that, although all samples exhibited similar phase compositions, pronounced differences in substructural characteristics were observed. Crystallite sizes ranged from 158 to 509 Å, while lattice microstrain varied from 0.17% to 0.645%, correlating with microhardness values between 1875 and 1912 HV. An optimal balance between hardness and plasticity, without evidence of embrittlement, was achieved at a sintering temperature of 1450 °C and a pulse current of 4500 A.
The main objective of reliability-centered maintenance is the cost-effectiveness of the maintenance strategy. These strategies, rather than the different components of reliability-centered maintenance being applied independently, are optimally integrated to take advantage of their respective strengths to optimize equipment reliability and life-cycle costs. The article uses reliability parameters to define the type of maintenance strategy and time to perform maintenance on gas compressors. This article presents a methodology using the gas compressor's reliability parameters to model reliability-centered maintenance procedure for the gas compressors. The approach is based on reliability parameters gotten from the liner regression carried out on the gas compressors. The shape parameter (β) from the Weibull linear regression shows that most components in the two gas compressors were experiencing early failure with their β < 1 and the distribution that best fits the data is the lognormal distribution, whose parameters are the shape parameter (σ') and the scale parameter (µ').
Manufacturing is dedicated to industrial production, in which raw materials are transformed into finished products on a large scale and included in the economy´s secondary sector. The Scopus database was used for the bibliometric analysis, based on the term {manufacturing}. The better result shows in the function of the number of documents produced: year 2023; source Proceedings of SPIE; author Franke J. and Wang, L.; affiliation Ministry of Education of China; country USA; document type article; scientific area engineering and funding support National Natural Science Foundation of China.
Manufacturing is dedicated to industrial production, in which raw materials are transformed into finished products on a large scale and included in the economy´s secondary sector. The Scopus database was used for the bibliometric analysis, based on the term {manufacturing}. The better result shows in the function of the number of documents produced: year 2023; source Proceedings of SPIE; author Franke J. and Wang, L.; affiliation Ministry of Education of China; country USA; document type article; scientific area engineering and funding support National Natural Science Foundation of China.
Using exothermic sleeves allows to reduce the volume of the risers required in the casting of ferrous alloys, as well as the amount of metal used, and the costs involved. In this work, flat plates of nodular iron were casted and the effects of the shape and size of the risers were analyzed. For this purpose, risers with two configurations (with and without exothermic sleeves), three shapes (cylindrical, spherical, oval), and two relative sizes (100% volume and 60% volume) were considered. The mixture that would experience a thermite reaction with the highest temperature was defined. Experimental tests and computational simulations were performed, indicating that the spherical sleeves result in the lowest porosity in the risers and the pieces. It was also found that the risers with exothermic sleeves and 60% of the base volume used satisfy the feeding requirements and reduce the defects in the piece.
Managing resource allocation for optimum effectiveness at various levels of maintenance activities is always a challenging task. Optimizing maintenance resources enables an organization to set priorities towards achieving certain goals which are availability and reliability of the equipment for operational excellence. The purpose of this analysis is to determine the optimum resources allocation proportions among the failure modes and to identify the failure modes that have the greatest cumulative effect on the equipment's downtime. This paper presents a methodology using the Pareto analysis in conjunction with failure mode effect and criticality Analysis in maintenance resources optimization. The approach is based on ensuring all failure mode criticality number are considered to obtain the significant failures mode that you should focus on as a priority. The analysis shows that failure mode; FM5, FM 3, FM 2, FM 12, FM 7 and FM 13 are confirmation to the Pareto principle, identifying that most of the downtime of the Instrumentation Air Compressors originated from these failure modes.
The article presents the results of studying the dynamics of changes in the porosity of two-component briquettes and pellets depending on the size of particles and the proportions of components in the mixture using an optimized packing of spheres. Knowing the patterns of change in the porosity allows to optimize the strength of the briquette and pellets as well as to improve their behavior in the reduction processes in blast furnaces, steel making furnaces and in direct reduction reactors. A computation experiment based on heuristic simulation model was designed to study the change of the estimated porosity under increasing/substituting the number of larger spherical particles in the mixture of spheres. The results obtained made it possible for the first time to reveal the extreme nature of the change in the porosity of the briquette/pellet with the addition of larger particles, depending on the fractional composition of the briquette. The results obtained open up new opportunities for optimizing the placement of fine-grained materials in the charge of metallurgical furnaces.
Ultrasonic ribbon bonding has gained much attention due to the endeavor of achieving higher module performance in power electronic packaging. Among all the ribbon materials, Ag ribbon is a promising candidate due to its superior electrical properties. However, research which has reported the bonding of the ribbon on chip side is scant. Thus, in this study, the authors carried out bonding of the Ag ribbon on various types of metallized wafers to examine the feasibility of Ag ribbon, simulating the bonding scenario on the chip side in power modules. Results revealed that bonding of the Ag ribbon is feasible on those wafers metallized Ag on top. The authors also discussed the implications for the bondability of Ag ribbon with different types of metallization layers.
Additive manufacturing is a popular emerging technology of producing parts directly from digital models. This technology has presented benefits such as freedom of design, the ability to customise, and shortened process chains. Presently, there are different Additive Manufacturing (AM) processes that are available in the market. Often, transport equipment manufacturing companies are faced with challenges while selecting the AM processes that are suited to their needs. Decision-makers need to consider all the underlining factors before a conclusion is reached. This paper proposes an approach that can be used by companies in the rail sector to select AM technologies that are suited to their applications. The approach involves identifying suitable parts, comparing applicable AM technologies and selecting the most suitable technology. The next stage involves re-designing the parts based on the selected technology. The approach is applied to benchmark parts from the industry. The study provides enlightenment on how AM can be applied in the rail industry.
Islands-Matrix-Dual-phase (I-M-DP) steel is received a great deal attention for better concern with the emissivity, fuel consumption and passengers safety. A number of deformation plasticity issues are yet to be fully understood. Complex deformation stages for various stain is predicted as the natural outfall of the plastic strain localization caused by the ill-assorted deformation between the martensite-island phase and the ferritic-matrix phase. Modeling is carried out both in macro level by bending under tension (BUT) for different roller radius/sheet thickness ratios to acquire strain and stress state deformation and micro scale by Representative Volume Element (RVE) according to element position. It can relate both the 2D, 3D micro and macro scale finite element based BUT model’s result of flow behavior. Systematically strain based severe deformation pattern arises from outfall of plastic strain localization and von Mises stress distribution in island-matrix steels are investigated on the microstructure by finite element method for ill-assorted deformation between phases.
The forming of low and high strength tailor welded steel sheets into preferred three-dimensional shapes by a homogeneous distribution of plastic strain is highly difficult. In this work, the formability of tailor-welded blanks prepared using laser welding of low (IS 513 CR2, IS 513 CR3) and high tensile strength (AISI 304) steel sheets were analyzed and the formation of the edge profile and weld line movement was also examined. The results showed a decrease in formability characteristics owing to the increase in Strength Ratio. Scanning Electron Microscope analysis of the fracture locations within unsuccessfully formed tailor welded blanks showed the presence of tempered martensite in the soft zone was found to be the most predominant factor affecting its failure. The formability characteristics of investigated tailored blanks were predicted using finite element simulation and compared with experimented results for validation.
Finite element simulation using ANSYS software, to analyze the effect of coating layers of different materials on piston compression ring. Similar material properties to that in the actual structural piston-compression-ring were considered on the simulated model. Three different coating materials, MgZrO3, La2Zr2O6, 3YSZ, and NiCrAl as bond coat materials of 1.6 mm thickness, were chosen to investigate the deformation, von Misses stress-strain, temperature distribution, heat flux of the core and coating layers. The results showed that the total elastic deformation was maximum for coating type MgZrO6, which was equal to 1.767 µm, and was higher by 0.46 times than uncoated ring. While, maximum von Misses stress was observed for coating type La2Zr2O6, which was higher by 1.69 times than that of the uncoated ring. Moreover, the maximum elastic strain was for type MgZrO6, which was equal to 0.003576, higher by 12.33 times comparing with the uncoated ring. Also, temperature rise and heat flux were maximum in the case of the uncoated ring.
This research develops a procedure for DEA window analysis and MPI evaluation of a manufacturing process with fuzzy inputs and outputs. A real case study was provided to illustrate relative efficiency and MPI assessment of a blowing machine over a period of one a year. The proposed approach was implemented to measure the technical, pure technical, and scale efficiency scores for decision making unit. The results showed that the blowing process was technically inefficient due to scale inefficiency. Therefore, management should optimize the size of operations and better utilize resources. Then, the lower and upper MPI values and their corresponding technology change and efficiency change were calculated. The MPI results revealed the reasons behind MPI progress or regress in current period measured with respect to next period. This procedure provides great assistance to process engineering in obtaining reliable feedback on process performance and guide them to take proper actions.
Duplex and super duplex materials possess the properties of both Austenite and Martensitic steels. Properties like hardness and toughness are very high for duplex grades and are difficult-to-machine. In this study, machining performance of Duplex Stainless Steel (DSS 2205) and Super Duplex Stainless Steel (SDSS 2507) was estimated during CNC dry milling operation. Cutting parameters namely feed rate, spindle speed and depth of cut were considered for this investigation and were optimized by considering surface roughness, cutting force and cutting temperature during CNC milling using Taguchi technique. Results revealed that depth of cut has more effect on cutting force than spindle speed and feed rate. Surface roughness was highly influenced by feed rate than spindle speed and least influenced by depth of cut for both the materials. Results also showed that, cutting temperature is mainly influenced by spindle speed. Optimum value for all the responses was obtained at spindle speed of 4200 rpm, feed rate of 50 mm/min and depth of cut of 0.35 mm for both DSS 2205 and SDSS 2507.
In the present work, an attempt was made to use vegetable oil as a cutting fluid during minimal fluid application to make the process more environmentally friendly. Coconut oil was selected as the vegetable oil in this study considering its availability, physical properties, and lubricating ability. The effect of newly formulated coconut oil-based emulsified cutting fluid on cutting performance during turning of hardened AISI 4340 steel with the minimal fluid application was investigated. It was observed that the coconut oil-based cutting fluid offered better cutting performance in terms of tool wear, surface roughness, cutting force, cutting temperature, and tool chip contact length when compared to mineral oil-based cutting fluid and raw coconut oil. It was also observed that the percentage of concentrate in the cutting fluid was to be maintained as 30% to achieve better cutting performance. The use of coconut oil-based cutting fluid holds promise as an environment friendly alternative for mineral oil-based cutting fluid.
Single point incremental sheet metal forming has passed through a period of ample improvement with developing responsiveness from research societies and industries globally. The process has expressively spared the practice of using costly dies, which makes it an appropriate process for manufacturing prototypes and small batch production. It also discovers easiness in fabricating components of timeworn equipment. Additionally, in recent years, aluminum alloys become the most commonly used materials in the automotive, aeronautics, and transportation industries for their structural and other applications. The effect of various process parameters on the formability of Single Point Incremental Forming of aluminum alloys has been critically surveyed. Ultimately, this article also debated the dares associated with the Single Point Incremental Forming process and recommended some correlated research regions which probably charm significant research considerations in the future.
Additive manufacturing is a popular emerging technology of producing parts directly from digital models. This technology has presented benefits such as freedom of design, the ability to customise, and shortened process chains. Presently, there are different additive manufacturing (AM) processes that are available in the market. Often, transport equipment manufacturing companies are faced with challenges while selecting the AM processes that are suited to their needs. Decision-makers need to consider all the underlining factors before a conclusion is reached. This paper proposes an approach that can be used by companies in the rail sector to select AM technologies that are suited to their applications. The approach involves identifying suitable parts, comparing applicable AM technologies, and selecting the most suitable technology. The next stage involves re-designing the parts based on the selected technology. The approach is applied to benchmark parts from the industry. The study provides enlightenment on how AM can be applied in the rail industry.
This paper aims to assess the dimensional deviation of Fused Deposition Modeling (FDM) processed ABS and ULTRAT parts using a new geometrical model which can evaluate three types of dimensional deviation: along the z-axis, along external and internal dimensions, and through diameters. The methodology involves a step-by-step procedure wherein after establishing the experimental plan and manufacturing the specimens, the measurements taken are analyzed via Grey Relational Analysis (GRA) to find out the optimal combination of parameters leading to the minimum deviation in all dimensions of parts for both materials. Statistical techniques such as Analysis of Variance (ANOVA) and Signal to Noise (S/N) ratio were also used. Subsequently, a confirmation test was carried out to validate the results obtained. The findings of the ANOVA and the S/N ratio were in good concordance with those of GRA.
Manipulation of robots is carried out by the operators through a sequence of commands. However, the accuracy of the manipulation is still hindered due to parameter uncertainty. This results in less accurate robotic operations and hence affects the job performance. Due to measurement errors and sensor faults, the operation of robots malfunctions. Generally, errors are reduced with the use of high precision sensors and correcting hardware faults. However, corrections can also be made on a software platform to handle the correction process. Presently, the Denavit–Hartenberg (DH) parameters of a robotic manipulator are optimized for forward kinematics problems. The optimization is carried out using the JAYA approach. The 6R MTAB Aristo XT robot is selected as a case study for the experimental validation of the proposed approach. Experimental results reveal that the optimization of DH parameters improves accuracy for forward kinematic estimation problems. The proposed JAYA approach can further be extended to other robotic manipulators for parameter optimization problems.
