Manufacturing Of Components Research Articles

Company Valuation and Influencing Factors: A Study of Automotive and Component Manufacturers Listed on the Indonesia Stock Exchange

The company's value is crucial as it reflects the company's performance, which can influence investors' perception of the company. The aim of this research is to determine the influence of profitability, company size, liquidity, and managerial ownership on company value in the automotive and component manufacturing sub-sector on the Indonesian Stock Exchange (IDX) for the years 2017-2021. The population in this study consists of manufacturing companies listed on IDX from 2017 to 2021, totaling 13 companies, with a sample size of 12 companies selected through purposive sampling method. This study employed multiple linear regression analysis to investigate the factors influencing company value. The results reveal that profitability and managerial ownership have a positive and significant impact on company value, while company size has no significant effect. Interestingly, liquidity exhibits a negative and significant relationship with company value. These findings suggest potentially important areas for future research. Expanding the study to include additional variables, such as leverage, capital structure, and dividend policies, could provide a more comprehensive understanding of the determinants of company value

Design, Manufacturing, and Evaluation of Race and Automotive Prototypal Components Fabricated with Modified Carbon Fibres and Resin.

This study explores the enhancement of Carbon Fibre Reinforced Polymers (CFRPs) for automotive applications through the integration of modified carbon fibres (CF) and epoxy matrices. The research emphasizes the use of block copolymers (BCPs) and electropolymerisation techniques to improve mechanical properties and interfacial adhesion. Incorporating 2.5 wt.% D51N BCPs in the epoxy matrix led to a 64% increase in tensile strength and a 51.4% improvement in interlaminar fracture toughness. The electropolymerisation of CFs further enhanced interlaminar shear strength by 23.2%, reflecting a substantial enhancement in fibre-matrix interaction. A novel out-of-autoclave manufacturing process for an energy absorber prototype was developed, achieving significant reductions in production time and cost while maintaining performance. Compression tests demonstrated that the modified materials attained an energy absorption rate of 93.3 J/mm, comparable to traditional materials. These results suggest that the advanced materials and manufacturing processes presented in this study are promising for the development of lightweight, high-strength automotive components, meeting rigorous performance and safety standards. This research highlights the potential of these innovations to contribute significantly to the advancement of materials used in the automotive industry.

Environmental Impact of Footwear Using Life Cycle Assessment—Case Study of Professional Footwear

Life cycle assessment (LCA) is a method for assessing the environmental impact of a product, activity, or system across all the stages of its life cycle. LCA can identify the activities with a major impact on the environment throughout the life cycle of a product. To analyze the environmental implications of footwear, the LCA was applied to a pair of shoes designed for professional use. In this paper, the impact of a single pair of shoes was studied. Every year, footwear production worldwide is over 22 billion pairs, which has a significant impact on the environment. In this case study, the “cradle-to-grave” approach was used, which refers to all the activities involved in the life cycle of a footwear product, starting from raw material extraction, manufacturing, use, maintenance, and, in the end, disposal. The LCA was conducted using the SimaPro software. The environmental impact assessment of the analyzed shoe needed the acquisition of two crucial datasets. Background inventory data were sourced from the Ecoinvent database (version 3.3). The impact was quantified using the Global Warming Potential (GWP) metric, which calculates the contribution of emissions to global warming over a 100-year time limit according to the established values provided by the Intergovernmental Panel on Climate Change (IPCC). The impact of greenhouse gas (GHG) emissions was measured in relative carbon dioxide equivalents (kg CO2eq) to facilitate a standardized comparison. The results show that the total carbon footprint for a pair of safety boots is 18.65 kg of CO2eq with the “component manufacture” stage as a major contributor accumulating almost 80%.

Fabrication and failure mechanisms of ultralight all-CFRP sandwich cylinders under axial compression

Ultralight all-CFRP honeycomb sandwich cylinders were fabricated using a stretching process. Subsequently, critical failure loads corresponding to five typical failure modes of the sandwich cylinders under axial compression were obtained through theoretical derivation. Three-dimensional failure mechanism maps were generated, which intuitively revealed the influence of the dimensionless parameters on structural failure. The panel thickness was selected as a variable, and quasi-static axial compressive tests were performed on the sandwich cylinders. Two failure modes, intracellular buckling and face crushing, were observed, which is consistent with theory. The experimental results were analysed and discussed systematically. The ultralight all-CFRP honeycomb sandwich cylinders were compared with existing cylinders to reveal their bearing advantages. The established failure mechanism maps provide guidance for the preparation and optimisation of honeycomb sandwich cylinders. Compared with the traditional fabrication processes of honeycomb cores, the novel stretching process is expected to achieve mass production, which is helpful to provide technical support for the lightweight manufacturing of aerospace structural components.

Driving the Transport Electrification: Exploring Stakeholders’ Perceptions and Actions in the Indonesian Automotive Industry Transition to Electric Mobility

The rise of all types of electric vehicles (xEVs) is reshaping the global automotive sector, marking a new era of electric mobility (eMobility). While existing research predominantly explores the transition towards eMobility from the perspectives of automakers, governments, and users, a notable gap exists regarding the role of internal combustion engine (ICE) component manufacturers. This research aims to examine the transformative journey of the Indonesian automotive industry, specifically focusing on the strategic responses of Indonesian ICE component manufacturers towards eMobility. This study employs a multi-level perspective (MLP) approach through 12 semi-structured interviews with stakeholders representing government bodies, associations, automakers, academia, startups, and ICE component manufacturers. This research sheds light on stakeholders’ perceptions and actions in the transition to eMobility. The findings reveal various factors influencing transition, including current low xEV demand, companies’ perceptions of xEVs, huge investments, changes in the supply chain, technological capabilities, and government policies. This research provides an overview of the strategies for ICE component manufacturers, along with their risks and advantages. This research also recommends two policies for the Indonesian government: a gradual transition and more support for local xEV and component manufacturing.

Coating-assisted picosecond laser ablation for microstructure fabrication of SiC ceramics

Silicon carbide (SiC) ceramics have emerged as critical materials in the production of high-precision components. Ultrafast laser processing is deemed the optimal technique for micro-nano manufacturing of SiC. However, the permanent deposition layer induced by laser ablation can critically impact the precision of the component. In this work, a coating-assisted picosecond laser ablation (CAPLA) method was proposed, in which sacrificial photoresist coating was utilized to improve surface quality without efficiency loss. The coating serves to prevent the uncooled plasma from contacting with the substrate, thereby preventing the formation of a permanent deposition layer. By comparing the CAPLA method with laser direct ablation, the influence of laser parameters and photoresist coating characteristics on the deposition layer was investigated systematically. A processed surface devoid of deposition layers can be achieved by CAPLA with low pulse energy and a high number of scans. The uniformity is critical to ensure the transmission of the laser beam, and a larger thickness can improve the processing efficiency by increasing the limit of pulse energy capacity. Pin arrays and vacuum grooves for SiC ceramic vacuum chucks were fabricated to demonstrate the superiority of the CAPLA method. These results suggest that this method can be a novel and promising approach for high-precision component manufacturing.

Exploring factors influencing aviation MRO services with blockchain technology in Taiwan

PurposeBlockchain is the fastest-growing technology currently being used in the aviation industry, especially in aviation maintenance, repair and overhaul (MRO) services. This study aims to create an analytic framework to assess the main factors and subfactors that have significantly influence the blockchain used in aviation MRO services. A mixed-methods approach is used to gain a comprehensive understanding of how blockchain is being adopted in aircraft maintenance facilities, Semi-structured interviews and questionnaires are used to gather data. The questionnaire is focused on the present state of the MRO industry.Design/methodology/approachBased on the literature review, a framework including four factors and 12 subfactors is developed, and the analytic hierarchy process (AHP) is then established. This study explores how these factors influence the implementation of blockchain in aviation MRO services. The five aviation MRO services providers in Taiwan, namely, “Evergreen Aviation Technologies Corporation,” “Taiwan Aircraft Maintenance and Engineering Co., Ltd.,” “Air Asia Company Ltd.,” “Aerospace Industrial Development Corp.” and “GE Evergreen Engine Services Corporation” are considered; furthermore, 55 experts working in these organizations were invited to evaluate the relative importance criteria in the AHP framework.FindingsThe results indicate that “inventory management” is the most important criterion, followed by “provisioning, procurement and sales” and “maintenance planning.” In addition, the three most important subfactors are “parts interchangeability,” “customer stock” and “SPEC2K interface for ATA SPEC 2000.”Originality/valueAsia is ranked as the second most important aviation MRO service market in the world. Taiwan has the shortest flight hours in the western Pacific region, the seven major foreign cities in this area. Aviation MRO service providers located in Taiwan are the best choices for aircraft MRO in the Asia-Pacific region, indicating that Taiwan serves as a promising market development evaluation model for blockchain aviation MRO services. The results offer a comprehensive overview of the relative importance of different criteria for MRO services that use blockchains. In addition, the findings present the market potential for key players in the aviation industry, including aircraft engineers, airline companies, aircraft component manufacturers and aviation MRO service providers.

Line Balancing Study Using Value Stream Mapping Tool on Lean Manufacturing: A Case Study in an Electronic Industry

XY Electronics, a leading international company in electronic components manufacturing, is confronting significant production constraints that adversely affect output, lead times, and operational expenses. This study examines the manufacturing line for product A using Value Stream Mapping to analyze process times and identify bottlenecks where takt times are exceeded. It focuses on areas surpassing production cycle times and aims to enhance line utilization through better line balancing and waste reduction. The results reveal that the header assembly, along with coplanarity and pre-testing 3, are major bottlenecks, which significantly impact productivity. By optimizing task allocation, refining workforce distribution, and employing cross-training, the production line efficiency improved significantly. In addition, strategic workforce reallocation and station optimization were crucial in addressing resource underutilization and enhancing overall operational efficiency

Effect of processing parameters and thermal history on microstructure evolution and functional properties in laser powder bed fusion of 316L

In this paper, we explain and quantify the causal effect of processing parameters and part-scale thermal history on the evolution of microstructure and mechanical properties in the laser powder bed fusion additive manufacturing of Stainless Steel 316L components. While previous works have correlated the processing parameters to flaw formation, microstructures evolved, and properties, a missing link is the understanding of the effect of thermal history. Accordingly, tensile test coupons were manufactured under varying processing conditions, and their microstructure-related attributes, e.g., grain morphology, size and texture; porosity; and microhardness were characterized. Additionally, the yield and tensile strengths of the samples were measured using digital image correlation. An experimentally validated computational model was used to predict the thermal history of each sample. The temperature gradients and sub-surface cooling rates ascertained from the model predictions were correlated with the experimentally characterized microstructure and mechanical properties. By elucidating the fundamental process-thermal-structure–property relationship, this work establishes the foundation for future physics-based prediction of microstructure and functional properties in laser powder bed fusion.

Guided Ultrasonic Wave Monitoring of Damage in Anisotropic Composites

Lightweight, carbon fibre reinforced composites are often employed for the manufacture of aerospace components due to their good strength to weight ratio. However, due to poor interlaminar strength, composite components are prone to barely visible impact damage, caused by low velocity impacts, during aircraft operation. Guided-wave-based structural health monitoring (SHM) techniques, using a network of distributed sensors, is an important Structural Health Monitoring (SHM) tool for the detection and localization of in-service impact damage in composite structures. However, the material anisotropy of composite laminates influences guided wave propagation and scattering. These anisotropic effects, if unaccounted for, could lead to inaccurate localization of damage, and potential regions of the structure where guided waves cannot propagate with sufficient amplitude, reducing damage sensitivity. Defect characterization can be improved by considering the scattering characteristics of various damage types for the sparse array signal processing. Guided wave scattering (A0 Lamb wave mode) was investigated around an artificial insert delamination in a quasi-isotropic CFRP panel. Permanent magnets, mounted on an undamaged region of the plate, were also used as scattering targets and compared to the delamination case. Full 3D Finite Element (FE) simulations were performed for both the delamination and magnet cases and compared to wavefield data obtained from non-contact laser Doppler vibrometer (LDV) measurements. Individual ply layers were modelled using unidirectional composite material properties to accurately capture the anisotropy effects. Good agreement was found between the experimental measurements and simulations. Scattered guided wave amplitudes around each damage type show strong directional dependency with energy focusing along the fiber directions of the outer ply layers of the laminate. Distinct scattering behavior was observed for each damage type. Implications of anisotropy and angular scattering on sparse array SHM of different defect types are discussed.

Research and application of continuous and precise nitrogen injection fire extinguishing technology in coal mines

To overcome shortcomings in traditional nitrogen injection fire prevention techniques, such as discontinuous nitrogen distribution, poor inerting effects, and severe waste of pipeline resources, a method for continuous and precise nitrogen injection fire extinguishing was proposed. To implement this method, this study utilizes FLUENT, FLAC 3D simulations, and principles of elasticity to determine the process and dynamic parameters of nitrogen injection. This information guides the selection, design, and manufacturing of equipment components, leading to the development of a novel “rotating towing type” continuous and precise nitrogen injection fire extinguishing equipment. Taking Wenzhuang 15,102 working face as an example, the inerting effect was compared and analyzed by using CO, Graham coefficient R2 (ΔCO/ΔO2), R3 (ΔCO/ΔCO2) and other quantitative indicators. The findings revealed following results: after deploying this equipment, there was an approximate 70 % reduction in CO concentration. Comparatively, R2 in the extraction area decreased by 45 % compared to the 0.38 % observed in the buried pipe nitrogen injection process. Similarly, the R3 values for the gob and upper corner were reduced by about 56 % and 60 %, respectively. These substantial improvements highlight the superior efficacy of the continuous and precise nitrogen injection fire extinguishing method for nitrogen injection and fire suppression in gobs.

Research on Decision Optimization of Supply Chain Quality Information Disclosure Considering Stigma Level

With the frequent occurrence of online public opinion events, the problem of product stigma is becoming increasingly serious. Enterprises must use effective quality information disclosure strategies to reduce losses affecting market sales and profit. Therefore, this paper aims to address the supply chain structure composed of one product manufacturer and one component manufacturer under the influence of stigma. It constructs a decision optimization model under three scenarios: no information disclosure, the product manufacturer disclosures information, and the component manufacturer disclosures information, and uses Stackelberg game theory to solve and analyze the model. Furthermore, we use numerical examples to verify the model results, and provide management suggestions for enterprises. The research results show that enterprises suffering from product stigma should actively implement information disclosure strategies to reduce their profit losses, and the lower the stigma level, the better the effect of information disclosure will be; when the stigma level becomes more serious, enterprises should take timely steps to reduce the sales price of products, the sales price of components, and the efforts to disclose information; for industries that value confidentiality of product information, although the implementation of information disclosure by the component manufacturer can require less effort for information disclosure, the two enterprises will suffer higher economic losses.

Will Congo move up the battery supply chain? Strategic capitalism, friendshoring, and localized manufacturing in the time of the green transition

In recent years, countries where extraction of so-called green minerals occur have increasingly asserted themselves. Negatively dubbed as resources nationalism, these political decisions are more akin to a willingness to increase in-country value added for regions often suffering from centuries of colonial extractivism. In the battery sector, these strategies led to cobalt, lithium, and nickel producers aiming to develop local manufacturing of battery components. This article provides a prospective analysis of these dynamics and takes the example of the Democratic Republic of the Congo and the recent announcement to establish the country as a supplier of cathodes materials and potentially even manufactured batteries. However, the road to becoming a midstream supplier is long and the current state of infrastructures presents significant barriers to a shift in the country's industrial base. Throughout this article, informed by ethnographic work, I address these challenges in the context of the low-carbon transition. The sustained post-colonial state of Congo's extractive complex and its location at the core of geopolitical competitions constitute a significant obstacle to the establishment of this new industry, while the metal-rich country tried to find its way and raison d'être in the volt rush currently underway.

The effects of electrolyte composition and deposition voltage on the copper-nickel alloy micropillars fabricated by Jet ECD

With the rapid development of micro electronic component technology, higher requirements are put forward for high performance and high precision manufacturing process. In this paper, copper-nickel alloy micropillars were manufactured by jet electrochemical deposition (Jet ECD) technology with high deposition rate, aiming to provide an effective material and process solution for the manufacture of micro-thermocouples and other components. By optimizing the process parameters such as electrolyte composition, pH value and deposition voltage, the homogeneous deposition of copper-nickel alloy micropillar was realized. The cross-section morphology and elementary composition of the deposition micropillars were characterized in detail by using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that the adjusted formula and process parameters can stably manufacture copper-nickel alloy micropillars with a nickel-copper ratio (close to 0.8), and compact, void free microstructure.

Microstructural control of LPBF Inconel 718 through post processing of intentionally placed AM discontinuity distributions

A major untapped potential of laser powder bed fusion (LPBF) is the ability to additively manufacture (AM) parts with site-specific properties. However, robust methods of improving performance and manufacturing efficiency via spatial variations in microstructure are underexplored.This work investigates a method of creating several distinctive multi-modal microstructures in the nickel superalloy, Inconel 718, by performing a Hot Isostatic Pressing (HIP) procedure on characteristic LPBF discontinuities such as keyhole and lack of fusion (LOF) porosity, as well as large powder filled voids. Observed using electron backscattered diffraction, this approach leads to the formation of site-specific variations in microstructure and extreme bi-modal microstructures. Processing AM parts via this method facilitates the production of fully dense, equiaxed, and strain free material culminating in a substantial time saving per layer. Further optimisation is required in order to achieve an optimum volume fraction and distribution of γ″ precipitates in each heat treated microstructure.

Effect of Vacuum Brazing Conditions of Inconel 718 Superalloy Sheets on Microstructure and Mechanical Properties of Joints

Vacuum furnace brazing is one of the most commonly used joining processes in the aerospace industry, utilized in the manufacturing of the complex components of turbine jet engines, working in both their cold and hot sections. The modern aerospace industry demands continuous improvement of production processes to enhance the engine performance, while ensuring its reliability. Therefore, a better understanding of the processes that shape the properties of engine assemblies joints is crucial. This paper presents an analysis of the influence of key brazing process parameters – brazing time and gap width – on the microstructure and mechanical properties of Inconel 718 superalloy joints obtained with the Palnicro 36M filler alloy. The analysis was conducted basing on results from SEM/EDS analysis and peel, shear and spreadability tests.

X-ray optics for the cavity-based X-ray free-electron laser.

A cavity-based X-ray free-electron laser (CBXFEL) is a possible future direction in the development of fully coherent X-ray sources. CBXFELs consist of a low-emittance electron source, a magnet system with several undulators and chicanes, and an X-ray cavity. The X-ray cavity stores and circulates X-ray pulses for repeated FEL interactions with electron pulses until the FEL reaches saturation. CBXFEL cavities require low-loss wavefront-preserving optical components: near-100%-reflectivity X-ray diamond Bragg-reflecting crystals, outcoupling devices such as thin diamond membranes or X-ray gratings, and aberration-free focusing elements. In the framework of the collaborative CBXFEL research and development project of Argonne National Laboratory, SLAC National Accelerator Laboratory and SPring-8, we report here the design, manufacturing and characterization of X-ray optical components for the CBXFEL cavity, which include high-reflectivity diamond crystal mirrors, a diamond drumhead crystal with thin membranes, beryllium refractive lenses and channel-cut Si monochromators. All the designed optical components have been fully characterized at the Advanced Photon Source to demonstrate their suitability for the CBXFEL cavity application.

Stacking Effect of Carbon/Glass Fiber During Drilling Operation of Laminated Polymer Composite

Nowadays, fiber stacks are extensively used in the aircraft and structural component manufacturing industries. It is mainly due to their excellent mechanical and physiochemical performances. The different stacking sequences of fiber materials expand the structural properties due to high-strength carbon fiber and low-cost glass fiber. The fragile and anisotropic conduct of Carbon (Cf) and Glass (Gf) laminates generates different types of complex machining issues. This article focuses on the Drilling test of Carbon/glass fiber hybrid composites using different stacking sequences. The effect of varying stacking orders is explored in this study to identify a feasible composite. The control of varying constraints, namely, spindle speed (N), feed rate (f ), and stacking sequence (SS) of carbon (Cf) and glass fiber (Gf) reinforcement, is performed to achieve the optimal parametric condition. The finding reveals that sample A (C4G4) stacking sequence provides an acceptable value for thrust force 59.05 N and delamination 1.0001 for high drilling efficiency. The stacking technique of carbon/glass layers can be endorsed to the manufacturing sector for cost-effective composite development and a defect-free machining environment.

RESEARCH ON THE INFLUENCE OF SECONDARY HEAT TREATMENT PARAMETERS ON THE MARTENSITIC STAINLESS STEEL PROPERTIES

Heat treatments constitute an essential stage for the possibilities of improving the mechanical properties of metal materials, such as hardness, mechanical strength and corrosion resistance. Any change in the heat treatment parameters, such as temperature, holding time and cooling rate, can influence the structure of the steel and cause the formation of the martensitic phase, responsible for increasing the hardness. Moreover, if the temperature and time are correctly selected, they can help eliminate internal stresses and imperfections in the crystalline structure, thus improving the strength and ductility of the steel. The hardness of martensitic stainless steel needs to be increased to meet the performance requirements for the applications in which it is used, such as the manufacture of knives, surgical instruments or components for the aerospace industry. Martensitic stainless steel is valued for its corrosion resistance and relatively low cost, and the hardness increase is essential to ensure proper operation and durability of products manufactured from this material. Any change in the martensitic stainless steel heat treatment parameters has a significant impact on increasing the hardness and improving its mechanical properties, being essential for obtaining the desired performance in various industrial applications.

Evolution and formation mechanism of residual stress in Al-Cu alloy rings during ring rolling and quenching

The large-scale ring components, as thin-walled structures, are prone to unpredictable machining deformation due to the initial residual stresses introduced by rolling and quenching, which seriously affect the dimensional accuracy and service life of the ring components. Therefore, the relief and homogenization of residual stress inside large-scale ring components is crucial. However, the existing studies rarely involve the essential causes and the evolution laws of residual stresses during the manufacturing of ring components, which are indispensable for understanding the failure mechanisms of components caused by residual stresses and specifying relevant protective measures. Therefore, the evolution and distribution laws of stress-microstructure-property non-uniformity during the hot forming (ring rolling) and heat treatment (quenching) of 2219 Al-Cu alloy rings were precisely and deeply explored using scaled experiments in this paper. The relationship between non-uniform deformation and residual stresses was analyzed, and the basic equation that residual stresses must satisfy was established. Furthermore, the concept of the “non-coordination coefficient” was proposed, revealing the physical mechanism of residual stresses induced by non-uniform deformation. In addition, the influencing factors and formation mechanisms of residual stresses in the rolled and quenched state of rings were studied, and the essential reasons for the differences in residual stresses between the rolling and quenching processes were obtained. The experimental results indicate that the circumferential and axial residual stresses increased from 1.48 and 0.51 MPa to −142.68 and −122.31 MPa, respectively. The standard deviation changed from 13.47 and 33.52 MPa to 63.42 and 61.61 MPa, respectively. The maximum range of tensile strength, yield strength and elongation rates of the rolling and quenched state is 12.82 and 20.16 MPa, 17.49 and 22.14 MPa, and 8.62 % and 7.56 %, respectively. All fractures are microporous aggregation ductile, including dimple transgranular fracture and intergranular fracture. The quenched state exhibits a significantly larger grain size compared to the rolled state. The appearance of residual stress is essentially to force the inconsistent deformation of various parts inside the object to maintain its integrity and continuity, which leads to a local mismatch of micro-elements inside the ring and further induces non-uniform strain and stress. The difference in the severity of “penetrability” induced by different temperature gradients determines the difference in residual stress between rolled and quenched rings, larger rings have higher and more non-uniform residual stress than smaller rings under the same process conditions. The above results deepen the theoretical understanding of residual stress formation mechanisms and lay a theoretical foundation for the comprehensive evaluation of performance degradation and service failure analysis of large ring components.