Remanufactured Parts Research Articles

Environmental and Economic Impact on Scenario-Based Automotive Part Replacement: Case Study of Constant Velocity (CV) Joint Replacement in Korea

The objective of this study is to comprehensively evaluate the environmental and economic impacts of remanufactured constant velocity (CV) joints using a newly proposed framework for automotive parts replacement. This framework utilizes actual vehicle sales data to accurately estimate the demand for CV joint replacements. Specific parameters are established to calculate this demand, enabling a quantitative assessment of both environmental and economic impacts associated with remanufacturing CV joints and other automotive parts. Additionally, sensitivity analyses are conducted to explore the relationship between environmental benefits and economic outcomes, particularly focusing on the preferences for remanufactured parts and their profitability. The results indicate that increasing the proportion of remanufactured CV joints significantly benefits the environment by reducing CO2 emissions, raw material usage, and energy consumption. However, this shift also leads to a decrease in total profits within the CV joint replacement market. To address this trade-off, the study suggests that financial incentives, such as subsidies or tax benefits, are necessary to support the remanufacturing industry and facilitate market expansion. These findings provide valuable insights for policymakers aiming to promote sustainable manufacturing practices through effective subsidy policies.

An investigation of mixed-model assembly line balancing problem with uncertain assembly time in remanufacturing

In recent decades, remanufacturing has emerged as an effective way to address resource crises and environmental pollution issues. Unlike traditional manufacturing, remanufacturing production is filled with various variable factors, especially in the assembly phase. Due to changes in part types, quality conditions, and assembly methods, the assembly time becomes highly uncertain. Assembly line balancing is a key challenge to achieve the stable operation of remanufacturing system. This study proposes an evaluation method for remanufacturing assembly time and establishes a multi-objective mathematical model for balancing remanufacturing mixed-model assembly (RMMA) line. The evaluation method utilizes the Fuzzy Graphical Evaluation Review Technique (FGERT) network to predict expected assembly time for each operation. The balancing model aims to optimize remanufacturing takt time and comprehensive balance rate (CBR). To effectively solve this model, an adaptive double-layer genetic algorithm (ADGA) is designed, where layer I ensures production efficiency and layer II optimizes assembly line balance. Finally, an assemble example of high-pressure common rail fuel pumps (HCRFP) is used to validate the effectiveness of the proposed method. The results demonstrate notable improvements compared to traditional single-product assembly (TSPA) line in scenarios with workstation numbers 4, 5, 6, and 7. Specifically, the production takt time is reduced by 4.19% to 9.56%, and CBR is enhanced by approximately 50%. Further comparison with three other classic algorithms confirms the superiority of ADGA. Additionally, it is observed that remanufacturability (proportion of remanufactured parts) has a significant impact on assembly performance. As remanufacturability increases, both takt time and CBR increase, reaching their maximum values when remanufacturability is around 0.5.

RESTORATION OF LARGE MODULAR TEETH OF BALL MILL GEARS BY ELECTRO-SLAG SURFACE

This article is devoted to researching the possibility of restoring straight-toothed large-module gears by electro-slag surfacing of individual defective teeth. During the work, an installation was designed and manufactured to restore gears that do not require further machining. A comparative analysis of the proposed technology with the traditional surfacing technique was carried out, paying attention to variables such as the composition of the surfacing material used, process parameters, stabilization of the electro-slag process, and ensuring the geometric dimensions and profile of the tooth. The study results demonstrate that the proposed technology provides higher hardness and wear resistance of remanufactured parts compared to traditional methods.

Assessment of greenhouse gas reduction through the utilization of remanufactured automotive parts, and consideration of the guidelines for product designs (Case studies of AC compressors, starters, and alternators)

Assessment of greenhouse gas reduction through the utilization of remanufactured automotive parts, and consideration of the guidelines for product designs (Case studies of AC compressors, starters, and alternators)

Quantitative Evaluation Model of the Quality of Remanufactured Product

Remanufacturing is a significant process for achieving carbon neutrality. However, the existing literature shows that consumer concerns regarding the quality of remanufactured products restrict the large-scale development of the remanufacturing industry. Studies on the quantitative evaluation of the quality of remanufactured products are limited. Therefore, we propose a quantitative evaluation model of the quality of remanufactured products. Extended from the formation process of the quality of remanufactured products, the quality loss function of remanufactured parts and assemblies was constructed based on Taguchi's quality concept. Subsequently, the relationship among social loss, functional limit, and quality loss of remanufactured products was assessed. Accordingly, a quality measurement model of remanufactured products was established. Moreover, the parameter estimation algorithm based on a neural network was evaluated to deal with the dynamic changes and uncertainties of remanufacturing technology and the remanufacturing market. Finally, the application of the proposed model was demonstrated through a case study in which the quality of remanufactured engines was quantitatively evaluated. The relevance of the model was verified through market feedback. This article can provide practitioners and decision-makers with new and effective tools and insights to improve the quality of remanufactured products and reduce the cognitive gaps of customers. It is expected to accelerate the high-quality development of the remanufacturing industry.

Centralized Restoration of Parts at the Enterprises of the Soyuzselkhoztekhnika and Goskomselkhoztekhnika Systems

Our country has been undergoing processes related to the reorganization and improvement of agricultural production services. The Soyuzselkhotechnika system was organized to replace the machine-technological stations. The development dynamics of Soyuzselkhotekhnika shows the volumes of marketable products, and it is particularly noted that the markup on all services used to be only 12.6%, and now it has risen to 45%. The volumes of reconditioning of parts at the enterprises of Soyuzselkhotekhnika are given; more than 60% of the names of parts were restored. Achievements of individual enterprises in the implementation of efficient technologies are shown. It is confirmed that the reconditioning of worn parts at the enterprises of Soyuzselkhotekhnika annually saved for the country up to 12% of new spare parts, over 500 000 tons of casting, and 150 000 tons of rolled products. The role of sectoral science and academic science is shown. The created system of Soyuzselkhotekhnika enterprises was an effective assistant for commodity producers not only in providing new machines and assemblies, but also for remanufactured parts with high quality, low price, and guaranteed performance.

SALE OF SECOND-HAND AND REMANUFACTURED COMPONENTS OF CONSTRUCTION EQUIPMENT: AN EMPIRICAL STUDY OF USER PERCEPTION IN ANDHRA PRADESH

The construction industry plays a pivotal role in shaping infrastructure and development, contributing significantly to economic growth and urbanization. In recent times, the sector has been seeking innovative ways to maximize efficiency, reduce costs, and promote sustainability. One promising avenue is the exploration of second-hand and remanufactured components for construction equipment, which has the potential to bring about substantial benefits for both businesses and the environment. This study explores the utility, availability, and compatibility of second-hand and remanufactured components for construction equipment, aiming to determine their potential to enhance machine productivity and contribute to revenue growth. The research methodology employs quantitative analysis to collect data from second-hand dealers across Andhra Pradesh. Additionally, consumer behavior is observed during the purchase of second-hand components, with a focus on relevant focus groups in this region. The study reveals that customer awareness and understanding of the technical aspects, usability, price comparisons, and compatibility of second-hand construction equipment parts are limited. Due to the lack of accessible testing facilities for remanufactured parts, customers often rely on their instincts and past experiences. Despite this, customers generally hold a positive perception of purchasing second-hand or remanufactured components. Furthermore, the high costs and scarcity of original parts at authorized dealerships drive customers towards buying components from the second-hand market.

Geometry and Microstructure Control of Remanufactured Metallic Parts by Cold Spray Additive Manufacturing.

Cold Spray Additive Manufacturing (CSAM) is a thermal spray technique that is typically used for the repair of metallic components. One of the challenges of CSAM is to improve the geometrical accuracy of the sprayed parts, along with overcoming the inferiority of the mechanical properties of the deposits by tailoring their microstructure with different deposition strategies. For this, Cu, Al, Ti, and Ti6Al4V substrates were reconstructed by two Cold Spray (CS) methods: Traditional (T) and a novel strategy, Metal Knitting (MK). The final geometry, microstructure, and mechanical properties of the reconstructed parts by these two methods were compared. Additionally, we investigated the effects of annealing on the microstructure of sprayed components and its influence on adhesion, resistance to erosion, and abrasive wear. The results indicate that annealing effectively reduces the microstructure defects of the remanufactured parts (up to 30% porosity reduction) and improves the adhesive strength (i.e., below 30 MPa for as-sprayed deposits, and up to 160 MPa for heat-treated Ti4Al4V deposits). Notably, the abrasive and erosive resistance of the Cu and Al annealed deposits sprayed by MK gave very similar results compared to their bulk counterparts, suggesting that it is an efficient method for the reconstruction of damaged parts.

A state-space model-based temperature control system for laser remanufacturing molten pool

ABSTRACT Laser remanufacturing is a key technology for remanufacturing, which has been widely used in aerospace, metallurgy, energy and other fields. However, the problem of shape control has been the bottleneck that restricts the scale and industrial application. In the laser remanufacturing process, the molten pool temperature is the critical to determine the shape and performance stability of remanufactured parts. Based on this, the paper proposes a real-time online control method for laser remanufacturing molten pool temperature based on state space model, which solves the problem of difficult to establish control mechanism model and multiple variable constraints. Develop a real-time online control system for molten pool temperature of laser remanufacturing process based on state space model and incremental integral separation PID control, which uses a single sampling point as temperature feedback, solving the problem of lag generated by traditional feedback cycle, realizing real-time online control of molten pool temperature of laser remanufacturing process. Finally, the experimental results show that the developed molten pool temperature control system can effectively eliminate the sudden and gradual temperature change in the deposition process and significantly improve the thermal accumulation phenomenon in the deposition process, thus improving the forming quality and performance stability of remanufactured parts.

How to attract newness-conscious consumers to a circular electric vehicle economy

Despite improved energy efficiency and reduced tailpipe air pollutants, electric vehicles (EVs) often encounter skepticism about whether EVs are a sustainable choice because of their waste management issues. The increased adoption of EVs worldwide will keep pushing the industry to adopt circular economy (CE) strategies such as remanufacturing. The study clarifies our understanding of the newness-conscious consumer (NCC) behavior in purchasing remanufactured EV parts. The NCC, which values newness and regards it as a proxy for product quality, is unlikely to be attracted to remanufactured products (RMPs) and constitutes a potentially unpredictable market segment for circular economy practitioners. We examine whether and how improving consumer awareness via green information provision can be pivotal in NCCs' purchasing behavior regarding RMPs in the EV industry. More specifically, we present a model to explain the NCC's purchase intention for remanufactured EV parts with various factors (green certification, perceived trust, perceived value, perceived knowledge of environmental benefits associated with remanufactured EV parts, and price consciousness) that may relate to providing green information. Based on an online survey of 600 participants characterized as NCCs living in Japan, the results of structural equation modeling showed that green certification influenced the NCCs' perception of trust and value regarding RMPs, which could, in turn, explain their purchase intention for remanufactured EV parts. NCCs' price consciousness appears to affect their perception of green certification. Mediation analysis results suggest that NCCs' perceptions of trust, value, and green certification mediate the relationship between their perception of remanufactured EV-related environmental benefits and purchase intention. In addition, we identify whether NCCs are reluctant to buy RMPs due to a lack of reliable green information that shows the value and functionality of remanufacturing. We showed half of the NCC respondents an informational video on RMPs and compared their responses to the remaining half of the group who did not watch it. Independent samples t-test results of the two groups (those with and without information) represented that providing NCCs with information on the functionality of RMPs might promote green purchasing behavior among NCCs. The findings of this study will provide CE practitioners, especially in the EVs industry, with a rich portfolio to cover previously unexplored market segments for remanufacturing.

Microstructure regulation and reinforcement mechanisms of ultrafine TiC/Fe55 composite coatings via laser melting deposition

The interfacial strength of phases are the main challenges that limit the service performance of metal matrix composites. In this paper, the influence mechanism of the ultrafine TiC particles introduced through both in-situ and external methods on the microstructure evolution, interfacial structure, phases distribution and wear resistance of Fe-based composite coatings by laser melting deposition were comprehensively investigated. It was found that the TiC particle in all prepared coatings was ultrafine scale with a pure interface. Particularly, the TiC particle added by the external method was presented as a composite structure in which the ex-situ TiC was wrapped with the in-situ TiC. For the in-situ method, as the (Ti + C) content increased (5–15 wt.%), the TiC particle changed from blocky to petal shape, and the wear volume was decreased and then increased. Compared with the adding of 10 wt.% nano-TiC externally, the coating with adding 10 wt.% (Ti + C) presented with greater wear resistant for its higher TiC content. The blocky TiC particles was beneficial to deflecting cracks and serving as wear-resistant skeletons due to the great interfacial bonding strength. This study provides a guidance for the preparation of high-performance Fe-based wear-resistant coatings for both newborn and remanufactured equipment parts.

Research on Assembly Sequence Optimization Classification Method of Remanufacturing Parts Based on Different Precision Levels

Aiming at resolving the problem of low assembly accuracy and the difficulty of guaranteeing assembly quality of remanufactured parts, an optimization classification method for the assembly sequence of remanufactured parts based on different accuracy levels is proposed. By studying the characteristics of recycled parts, based on the requirement that the quality of remanufactured products not be lower than that of the assembly quality of new products, the classification selection matching constraints of remanufactured parts are determined, and the classification selection matching optimization models of remanufactured parts with different precision levels is established. An algorithm combining particle swarm optimization and a genetic algorithm is proposed to solve the model and obtain the optimal assembly sequence. Taking the remanufacturing assembling of a 1.4 TGDI engine crank and a connecting rod mechanism as an example, the comparison of quality data shows that this method can effectively improve the qualified rate of assembly, reduce the cost of after-sale claims, provide new theories and methods for remanufacturing enterprises that need hierarchical assembly, and provide effective guidance for the development of the remanufacturing industry.

Quantitative benefits of the digital product passport and data sharing in remanufacturing

As a part of the circular economy – which aims at closing the loop of materials – remanufacturing is getting more and more attention in recent years. With remanufacturing, companies are carrying out a recovery operation of used products with the aim of rebuilding a like-new condition. As various members of the supply chain are involved in this process, and product data needed for optimal operation is often missing, remanufacturing processes can become uncertain and hard to optimize. The goal of a new European Commission initiative, the digital product passport (DPP), is to facilitate information exchange between stakeholders, in order to reduce uncertainties. DPP, assigned to a product, could contain information about e.g., its origin, composition, repair and dismantling possibilities. In the paper, the essence of DPP is introduced, and a case study is presented to show the qualitative benefits of the increased amount of information about the product. A discrete event-based simulation model of three real production lines that are (re)manufacturing cylinder heads is presented. Experiments are also conducted, where quantitative benefits of using DPP are highlighted, such as decreasing unnecessary production time, increasing ratio of remanufactured parts and increasing output.

Системний підхід до формування показників якості відновлених деталей

The paper considers the technological process of parts restoration as a system of interrelated elements that can influence the formation of quality indicators of restored parts. It is established that the technological process has all the necessary properties that are required for systems. However, modern methods and criteria used in the design of the technological process of parts recovery focus on the selection of the optimal recovery method, which is only part of the technological process. Therefore, the paper sets the goal of presenting the technological process of restoration as a system of interconnections between individual elements that allow to purposefully influence the quality indicators of restored parts. The main hierarchical levels of technological design of part recovery are defined. In turn, the technological process of restoration as a whole is presented in the form of functions of connections between individual elements of the subsystem. This made it possible to present the overall structure of the technological process of restoring worn parts as a system. Taking into account the peculiarities of the system's functioning, an approach is proposed, according to which all elements of the system have an impact on the formation of quality indicators of the restored parts. The functional links between quality indicators and elements of the technological process at different levels of evaluation are established. The main ways to ensure the required quality indicators through the elements of the technological process are determined: methods, equipment, materials, modes, equipment, etc. The proposed approach to the formation of quality indicators of remanufactured parts makes it possible to study the cause-and-effect relationships between the parameters of technological processes and quality indicators of remanufactured parts, as well as to establish ways to improve them. The ways to ensure the quality of remanufactured parts at the main stages of the product life cycle are shown.

Effects of laser energy density and path on residual stress of remanufactured key components for shield tunneling machine

Due to the abrasion and high cost of key components for shield tunneling machines, the failed or worn components are remanufactured by laser melting deposition (LMD) with paraxial powder feed. However, the residual stresses distributed in the cladding layer reduce the service life of remanufactured parts. In this paper, an experimental study is presented on residual stresses along the depth direction of cladding with varied laser energy density and deposition path. Residual stress in Fe-based coating and heat-affected zone (HAZ) is characterized by X-rays with the method of layer-removal. The microstructural evolution and the phase structure of laser deposited cladding layers are analyzed. The results indicate that the residual stresses, in the range of −624 to −86 MPa in the cladding layer, are mainly compressive while the tensile stresses (in the range of 200–550 MPa) are primarily in the heat-affected zone (HAZ). With the increase of the thickness of the cladding layer, the depth of the zero stress layer increases. The main phases in the cladding layer are α-Fe and γ-Fe. The microstructure in the top layers of the cladding consists of fine, equiaxed grains while in the lower layers, the grains are distinctly cellular.

Research on the friction and wear performance of remanufactured shaft parts of failed machine tools

In this paper, the shaft parts of failed machine tools were treated by laser cladding, and the shaft surface of 45# steel matrix was repaired. The microstructure, hardness and corrosion resistance of the cladding layer and quenched phase transformation zone were analyzed by metallographic microscope, Vickers microhardness tester, and friction and wear tester. The laser cladding layer was tested by friction and wear tester. The results showed that the friction coefficient of laser cladding layer was only 0.58, and it fluctuated slightly. The corrosion resistance of laser cladding layer was obviously increased.

Error propagation model and optimal control method for the quality of remanufacturing assembly

In order to improve the quality of remanufacturing assembly with uncertainty for the sustainability of remanufacturing industry, an error propagation model of the remanufacturing assembly process and its optimal control method are established. First, the state space model of error propagation is established by taking the work-in-process parameter errors of each process as the initial state of the procedure and the parameters of remanufactured parts and operation quantities as the input. Then, the quality control issue of remanufacturing assembly is transformed into a convex quadratic programming with constraints based on this model. Finally, the proposed method is used to control the remanufactured-crankshaft assembly quality. The experimental results show that the axial-clearance consistency and the crankshaft torque are improved, and the one-time assembly success rate of a remanufactured crankshaft is increased from 96.97%to 99.24%. This study provides a theoretical model and method support for the quality control of remanufacturing assembly and has a practical effect on improving the quality of remanufactured products.

Microstructure and properties of metal parts remanufactured by laser cladding TiC and TiB2 reinforced Fe-based coatings

Laser cladding process, an efficient surface remanufacturing method, has become a research hotspot in recent years. Herein, in situ titanium carbide (TiC) and titanium diboride (TiB2) reinforced composite coatings were fabricated on the surface of damaged carbon steel to improve the hardness and wear resistance of remanufactured parts. Effects of addition of 5B4C and 15Ti (in wt.%) powder on morphology, phase composition, microstructure, and mechanical properties of specimens were comprehensively investigated. Results revealed that milled groove could be effectively filled with composite coating, which formed good metallurgical bonding with the substrate. Furthermore, sequentially precipitated in situ synthesized phases including TiC, TiB2, Cr3C2, Fe2B, and Fe3C in composite coating could continuously increase nucleation sites and further refine grains. Moreover, uniformly distributed reinforcements effectively weakened the directivity of heat flow during solidification process and promoted columnar to equiaxed transition. Mechanical properties illustrate that micro-hardness of composite coating with 961.94 HV0.3 is 4.14 and 5.04 times, and corresponding volume loss is 7.8 and 2.8 less than those of 316 L coating and standard 45 steel, respectively. This study indicates that in situ formed ceramics reinforced composite coating can act as an ideal candidate for remanufacturing damaged parts, and further improve their wear resistance.

A novel method for residual life assessment of used parts: a case study of used lathe spindles.

In the remanufacturing evaluation process of used spindles, the remaining life of each type is very different due to the differences in the original process, quality, and use conditions. Researching the prediction and evaluation of the remaining life of used spindles has essential engineering significance for improving the accuracy and economics of remanufacturability assessment. Aiming at the fatigue fracture, wear and excessive deformation of the wasted spindle, and considering the factors affecting crack closure and crack development, a residual life prediction evaluation model based on a nonlinear continuous fatigue damage model was proposed. Take the spindle of CAK5085 CNC lathe of a machine tool company as an example to evaluate its remaining life. The accuracy and feasibility of the modified model are verified by comparing the data of the test with the calculated results of the model. The results show that the proposed prediction model can calculate a more accurate stress-life curve, which provides a theoretical basis for the life prediction of remanufactured parts.

Improving the properties of remanufactured wear parts of shield tunneling machines by novel Fe-based composite coatings

With the aim of remanufacturing high-value wear parts of shield tunneling machines, novel Fe-based composite coatings were prepared by collaborative modification with nano-TiC and nano-CeO2 particles. This work aims to improve the wear properties of Fe-based alloy coatings by regulating the morphology and dispersion of TiC through the addition of different contents of nano-TiC and nano-CeO2. First, the coatings with different contents of nano-TiC (from 5 wt% to 15 wt%) and nano-CeO2 (from 1 wt% to 2 wt%) were prepared by laser cladding. Subsequently, the microstructure, phase composition, microhardness, and wear properties of the coatings were examined. Furthermore, the wear morphology and the influence mechanism of nano-particles on the wear resistance of the coatings were investigated. It was found that the addition of nano-TiC eliminates the macro-defects of Fe55 alloy coating. Meanwhile, the morphology and dispersion of TiC particles in coatings were affected by the content of nano-TiC and nano-CeO2. Specifically, the addition of 1 wt% nano-CeO2 facilitates to the formation of near-spherical tiny TiC particles with low agglomeration in the coating. Therefore, the Fe55 + 10 wt% nano-TiC+1 wt% nano-CeO2 coating exhibits the best wear property among all the prepared Fe-based coatings. This paper provides theoretical guidance for the preparation of the modified Fe-based coating with excellent wear resistance.