Hybrid Remanufacturing Research Articles

Research on hybrid remanufacturing process chain of laser cladding, CNC machining and ultrasonic rolling for aero-engine blades

There are high geometric accuracy and mechanical performance requirements in the repair and remanufacturing process for aero-engine blades. Therefore, a synergy of multiple processes is necessary for blade repair. This paper mainly studies the coupling relationship between multiple processes of aero-engine blade repair and the influence and contribution of each process to the final surface integrity of the blade. Firstly, a hybrid remanufacturing process chain of laser cladding, CNC machining and ultrasonic rolling is proposed for the requirements of blade repair. Then, a numerical model of the geometric feature construction and transient thermal and structural behavior in the hybrid remanufacturing process chain for blades is established. Finally, the interaction law among the three processes of laser cladding, CNC machining and ultrasonic rolling is analyzed. The results show that a larger powder feed rate is allowed in the laser cladding process of the hybrid remanufacturing process chain for blades. Thermal deformation and residual stress caused by high powder feed rate and thin-walled structure can be optimized by CNC machining and ultrasonic rolling. In addition, the influence mechanism of the three processes on the final surface integrity is revealed. It is shown that the effects of the hybrid remanufacturing process parameters on the remanufacturing quality are different from that of the traditional process. The feasibility of the hybrid remanufacturing process chain for blades is illustrated by the verification experiment on the damaged blade.

The Impact of Return Disposal on Order Variance in a Hybrid Manufacturing and Remanufacturing System

The Impact of Return Disposal on Order Variance in a Hybrid Manufacturing and Remanufacturing System

Gradient Structure Design and Welding-Hammering Hybrid Remanufacturing Process of Continuous Casting Rollers.

To improve the service life and reduce the repair cost of continuous casting rollers, a new welding-hammering hybrid remanufacturing process in which the roller was designed with a gradient structure was proposed, and corresponding equipment was developed. First, the failure modes and their causes for a continuous casting roller were analyzed by numerical simulation. The cyclic tension-compression shear stress, cyclic tension-compression normal stress, thermal cycle, and highly corrosive environment caused fatigue cracking and overall peeling of the roller surface. Second, the gradient structure composed of a base layer, transition layer, and strengthened layer of a continuous casting roller was designed, and materials for each layer were selected according to their different service conditions. Third, novel equipment for continuous welding-hammering composite remanufacturing was developed, and the optimized process parameters were obtained through welding experiments. Finally, an application test was carried out; the microscopic analysis showed that refined grains, fewer welding defects, and better surface toughness were obtained. Compared with traditional remanufacturing processes without hammering, the welding-hammering hybrid process achieved a forged structure instead of as-cast structure, which significantly improved the service life of the continuous casting roller by about 100%.

Construction of damage-free digital twin of damaged aero-engine blades for repair volume generation in remanufacturing

Accurate repair volume generation from 3D scan data of damaged aero-engine blades is of great importance in additive or hybrid remanufacturing for restoring the blades to a like-new condition. In addition to material-missing damages, the blade's surface also deforms due to working in harsh environments, which makes it deviate from the nominal design geometry. Therefore, the Boolean operation between the nominal CAD model and the scanned point cloud of the damaged blade does not yield an accurate repair volume. This paper presents a new methodology to construct an accurate damage-free digital twin model of the defective blades that contains the deformations of the blade's undamaged regions. The Boolean difference between the scan data of the damaged blade and its damage-free digital twin yields the repair volume with a smooth geometric transition at the interface of the repair patch and unrepaired regions. At first, the data points of damaged regions of the blade surface are detected and eliminated from the scan through a region growing segmentation. Then, a CAD-to-scan non-rigid registration algorithm deforms the nominal CAD model of the blade to best match it to the scanned point cloud in the undamaged regions. The non-rigid registration algorithm iteratively minimizes the distance between two datasets under the local rigidity constraint to avoid shrinkage and expansion of the deformed CAD model. A constrained point-to-surface weighted correspondence search method is proposed to reduce the influence of noise and unreliable correspondences on the non-rigid registration. The results of numerical and experimental case studies have demonstrated that the proposed method is accurate and robust to noise, and it can be effectively applied to construct a damage-free digital twin model for repair volume generation.

Investigative on the remanufacturing process of TC4 blade based on selective laser melting and CNC machining

This paper process a self-adaptive hybrid remanufacturing process of TC4 blade based on the additive manufacturing and CNC machining. The requirement of mechanical properties of the blade remanufacturing process is firstly introduced. The process flow of self-adaptive hybrid manufacturing process of TC4 blade based on the selective laser melting and CNC machining is then processed. The mechanical properties of the remanufacturing area, the transition area, and the matrix area of blade are thirdly analyzed by the FEA and the mechanical experiment. The feasibility of the proposed process method is finally verified by a case blade remanufacturing experiment. The results show that the remanufacturing area, the transition area and the matrix area are of good metallurgical bonding effect. The tensile properties of the remanufacturing area and the transition area after the hybrid remanufacturing process have reached the tensile properties standard of TC4. The impact toughness value of the transition area of TC4 blade is higher than that of the remanufacturing area, and the transition area after the hybrid remanufacturing process has better impact resistance. The blade remanufacturing experiment verified that the self-adaptive hybrid remanufacturing process is feasibility to obtain the sufficient mechanical property of the remanufacturing area and the transition area.

Investigation on repairing 30CrMnSiNi2A steel with laser additive and subtractive hybrid remanufacturing technology

The 30CrMnSiNi2A ultra-strength steel features excellent comprehensive mechanical properties and has been widely used to manufacture structural parts such as the aircraft landing gear, the wing girder, the missile engine shell, etc. However, wear and defects are produced on the surface of these parts in the course of their long-term service. In this paper, a continuous-wave laser deposition and pulsed laser finishing hybrid technique was proposed to repair 30CrMnSiNi2A ultra-high strength steel. The microstructure and mechanical properties of 30CrMnSi2A alloy matrix, laser repairing and laser finishing parts were compared. Laser finishing parameters were optimized to further improve the surface properties of the repaired parts. The effect of different process parameters on the surface morphology, microstructures, micro-hardness and wear resistance was explored. The results revealed that the comprehensive surface properties of repair parts with an average surface roughness of 1.12 µm, a micro-hardness of 595.22HV and a wear rate of 4.78 × 10−3 mm3/N·m can be obtained with laser finishing. And, the surface roughness and wear rate were reduced by 64.96% and 27.68% respectively, and the micro-hardness can be improved 23.67% compared with the parts without laser finishing.

A Mass-Customization-Based Remanufacturing Scheme Design Method for Used Products

Remanufacturing scheme design (RSD) is an essential step in the restoration and upgrading of used products. However, the quantity of remanufactured products is growing rapidly, and customers have personalized demands for remanufactured products that lead to shorter design cycles. In addition, the used products are scrapped due to their own defects, such as performance failure and functional degradation, which correspond to the inherent remanufacturing demand (IRD) of used products. Faced with large quantities of used products, how to quickly develop reasonable remanufacturing schemes for satisfying customers’ individual demands and the IRD is an urgent problem to be solved. To address these issues, a mass customization-based RSD method is proposed. First, remanufacturing demand comprising customer demand and the IRD is analyzed to determine the RSD targets and remanufacturing types. Then, the RSD methods are intelligently selected based on the remanufacturing types, which include restorative remanufacturing, upgrade remanufacturing and hybrid remanufacturing, while the hybrid contains restorative remanufacturing and upgrade remanufacturing. Moreover, the restorative remanufacturing scheme is generated to satisfy the restorative remanufacturing targets based on reverse engineering (RE) and the tool contact point path section line (TCPPSL) method. After used products are restored, case-based reasoning (CBR) is used to retrieve the case that best matches the upgrade remanufacturing targets, while the grey relational analysis (GRA) algorithm is applied to calculate the similarity between cases. Finally, the feasibility of this method is verified by considering the RSD of a used lathe. The results indicated that the proposed approach can rapidly help designers to obtain remanufacturing solutions for satisfying the customer demand and IRD.

Microstructural evolution and tensile property enhancement of remanufactured Ti6Al4V using hybrid manufacturing of laser directed energy deposition with laser shock peening

Laser-directed energy deposition (LDED) provides an attractive and cost-effective way to remanufacture high-value engineering components. However, the LDED manufactured (LDEDed) components are usually characterized by large columnar grains along the deposition direction, leading to mechanical anisotropy. Meanwhile, higher performance is usually required in the damaged regions. In this paper, the effects of interlayer laser shock peening (LSP) treatment, namely, an innovative laser hybrid additive manufacturing technology combined LDED with LSP, on microstructural evolution and mechanical performance of Ti6Al4V alloy were investigated. Particularly, the microstructural features between adjacent deposited layers were clarified using scanning electron microscope (SEM) and transmission electron microscopy (TEM) observations. The results indicated that the epitaxial growth of columnar grains caused by LDED was inhibited, and fine equiaxed grains were formed between deposited layers due to the recrystallization behavior. Besides, the microhardness and tensile property of the LDEDed specimen were significantly improved by the interlayer LSP treatment. Consequently, the laser hybrid additive manufacturing -generated dominant mechanism of the microstructural evolution and tensile property enhancement was revealed. • LSP was combined with LDED to realize the laser hybrid remanufacturing. • Epitaxial growth of columnar grains in the LDEDed specimen was inhibited by LSP. • The micro-hardness of the LDEDed specimen was significantly improved by LSP. • A good combination of UTS and ductility was achieved in the LDED-LSPed specimen. • The mechanism of the tensile property enhancement by LHAM was revealed.

Disruption management for a remanufacturer with dual collection channels

ABSTRACT Disruptions caused by many factors, such as epidemics and policy uncertainties, affect the recycling of used products. This paper investigates a closed-loop supply chain where a remanufacturer collects from customers (online channel) directly or a third party (offline channel). When collection channel disruptions happen, the remanufacturer can close the disrupted channel or implement a delay strategy. The results show that no matter with or without the delay strategy, disruptions are always harmful, and the online disruption causes more damage than the offline disruption. Furthermore, the delay strategy is always better for the remanufacturer. However, with the delay strategy and customer transferring, the online disruption may damage less, and we surprisingly find that the online disruption may increase recycled quantity and firms’ profits when with high transfer ratio; moreover, the complete online disruption may perform better than partial one; finally, the hybrid remanufacturing strategy can alleviate the damage of offline disruption.

A dynamic decision-making framework for a hybrid production system for decayed merchandise with shortages in traditional and electronic markets

This research proposes a dynamic decision-making framework for a hybrid production system that incorporates manufacturing and remanufacturing procedures into a closed-loop supply chain network with merchandise substitution and shortages within traditional markets (TM) and electronic markets (EM). In particular, we develop models of profit maximization and equilibrium analysis by using calculus with dynamic programming under four business schemes, including a manufacturing-only model within TM/EM and a hybrid remanufacturing model within TM/EM. Dynamic decision-making planning was taken for brand-new and like-new decayed merchandise in hybrid production systems. The results demonstrate that solutions generated within EMs surpass those within TMs in terms of maximizing profits. Further, the hybrid remanufacturing model did not surpass the manufacturing-only model under a general setting, but had better performance under certain conditions, including intense competition, a smaller remanufacturing cost, a larger brand-new merchandise market size, and a smaller like-new merchandise market size.

A cost-driven process planning method for hybrid additive–subtractive remanufacturing

Hybrid manufacturing combines additive manufacturing’s advantages of building complex geometries and subtractive manufacturing’s benefits of dimensional precision and surface quality. This technology shows great potential to support repairing and remanufacturing processes. Hybrid manufacturing is used to repair end-of-life parts or remanufacture them to new features and functionalities. However, process planning for hybrid remanufacturing is still a challenging research topic. This is because current methods require extensive human intervention for feature recognition and knowledge interpretation, and the quality of the derived process plans are hard to quantify. To fill this gap, a cost-driven process planning method for hybrid additive–subtractive remanufacturing is proposed in this paper. An automated additive–subtractive feature extraction method is developed and the process planning task is formulated into a cost-minimization optimization problem to guarantee a high-quality solution. Specifically, an implicit level-set function-based feature extraction method is proposed. Precedence constraints and cost models are also formulated to construct the hybrid process planning task as a mixed-integer programming model. Numerical examples demonstrate the efficacy of the proposed method.

Feature extraction and process planning of integrated hybrid additive-subtractive system for remanufacturing.

Discussion regarding hybrid manufacturing has dominated research in recent years. By synergistically integrating additive and subtractive manufacturing within a single workstation, the relative benefits of each manufacturing strategy are leveraged. The ability to add, remove feature flexibly enables remanufacturing end-of-life components into a "new" part with new features and functionalities. However, in the remanufacturing context, the process planning for hybrid additive-subtractive manufacturing is still an unsolved research topic. In general, a hybrid remanufacturing process is signified by an alternating sequence of additive and subtractive operations that alternatively add and remove materials on a used part, which results in a non-unique process planning. For determining an optimal sequence for hybrid remanufacturing, a quantitative evolution mechanism is demanded. Moreover, the constraints in process planning are required to be considered. For example, the collision avoidance between the workpiece and the material-dispensing nozzle is one of the most critical limitations that affect the alternating sequence. To fill the gap, automated feature extraction and cost-driven process planning method for hybrid remanufacturing are proposed in this paper. The feature extraction, developed under the level set framework, can extract optimal and collision-free additive-subtractive features. Then, the hybrid process planning task is formulated into an integer programming model with cost estimations. A case study is conducted, and the results confirm the correctness and effectiveness of the proposed method.

A hybrid circular economy - Game theoretical approach in a dual-channel green supply chain considering sale’s effort, delivery time, and hybrid remanufacturing

The circular economy (CE) and the marketing activities are the key subjects to attract the market share in today’s complex supply chain. Here, dual selling channels, the online delivery time, and the distributor sales effort are considered as marketing activities to attract the customers. Moreover, in order to meets the economic and environmental principles of the CE, three responsibilities to ease the carbon emission, as approaches for the return on investment, are devised, including investment in the green production, the cap and trade regulation, and the hybrid remanufacturing via both the manufacturer and the distributor under the technology license. This such complex supply chain needs to determine the equilibrium amounts of the distinguishing elements, including the pricing strategy, remanufacturing approaches, delivery time, and sales effort to abate the conflicts between the members, and consequently, to enhance the economic and CE objectives of the supply chain (SC). In order to obtain the equilibrium decision makings, three game theoretical approaches, including the manufacturer-Stackelberg game (SM), the distributor-Stackelberg game (SR) and the Nash game (N) are employed. The interaction between the game sequences and the remanufacturing process is the key purpose of this paper to not only maximize the profit of SC but also to enrich the CE and marketing goals of this research. The outcomes presented that the SM game, where the manufacturer remanufactures most of the defected products which are collected via the distributor, is the best game strategy to improve the profits of both the distributor and the manufacturer, and also to enhance the other distinguishing elements. In addition, in the SR game, when most of the returns remanufacture via the distributor under the manufacturer license, it not only maximizes the profits of members but also lead to the improvement of the distinguishing elements. In the Nash game, however, there is a conflict between the members about the remanufacturing process, which reduces the SC profit in this game as compared to other ones.

A closed-loop supply chain considering carbon reduction, quality improvement effort, and return policy under two remanufacturing scenarios

In today's competitive supply chains, providing products which can stimulate the customer's demand and enhance the revenues of companies is an important objective. Therefore, three stimulating factors, including the carbon emission reduction, return policy and quality improvement efforts are taken into consideration in a supply chain (SC). In line with reducing carbon emission, two possibilities in the forward flow, including the technologies investment and the trade and cap are employed. In the reverse flow, hybrid remanufacturing of the imperfect quality products under technology license is investigated. The impacts of collecting-remanufacturing processes on carbon reduction, quality improvement, and SC performance are the key objective of this research. Therefore, two collecting-remanufacturing scenarios, namely A and B, are introduced to analyze the interactions between the abovementioned motivating factors. In Scenario A, the distributor collects the returns paying the refund price, while both the manufacturer and the distributor remanufacture the returns in the hybrid form under a technology license. In Scenario B, however, the third party is added to collect the returns, while the manufacturer and a third party remanufacture the products, where the distributor is only responsible to transfer and sell the products to the customers. The findings illustrate that under all remanufacturing rates investigated, the SC profit under Scenario B is more than that of Scenario A. Moreover, the interactions among the motivating factors are presented, in which a higher refund price has positive effects on the carbon reduction, quality improvement, and SC's profit. Furthermore, employing all of the stimulating factors simultaneously is an effective approach to increase SC performance environmentally and economically.

Analysis for recycling and remanufacturing strategies in a supply chain considering consumers’ heterogeneous WTP

Empirical and theoretical research has shown that consumers’ willingness to pay (WTP) has a significant impact on manufacturers’ decisions. Based on these findings, we establish models for multiple remanufacturing modes considering WTP heterogeneity or different remanufactured products, in one-period and two-period closed-loop supply chain (CLSC) scenarios, to identify the optimal recycling and remanufacturing decisions of manufacturers. We find that manufacturers should participate in remanufacturing in one-period or two-period settings to earn more profits. In the one-period scenario, hybrid remanufacturing is better for the manufacturer than single remanufacturing, and the manufacturer chooses its remanufacturing partner based on the lower remanufacturing cost. In the two-period scenario, when the WTP ratio is above a certain threshold, the manufacturer chooses the third party as its joint recycling partner to obtain higher consumer surplus, a higher recycling rate, and higher profits. If the WTP ratio is high enough, hybrid remanufacturing is better for the manufacturer. The manufacturer does not authorize the distributor to engage in remanufacturing, for this choice yields the lowest profits for the manufacturer independent of WTP ratio. These results have policy implications from the perspective of CLSC cooperative recycling and remanufacturing.

A Topology Optimization Method for Hybrid Subtractive–Additive Remanufacturing

This paper presents a hybrid subtractive–additive remanufacturing oriented topology optimization method. This method provides a design-for-remanufacturing approach, which offer solutions for product upgrade or repair. To be specific, a used part is first machined to remove material, and then additively deposited of materials on top. In this way, either the function of the part is upgraded or the broken part is repaired. Beneficially, the used part is economically and environment-friendly recycled. This method is developed under the level set framework and innovatively, the layer-wise level set representation of the additive manufacturing part is adopted for self-support and material anisotropy control. Especially for the latter point, the hybrid deposition path, a combination of contour-offset and zig–zag path patterns, is adopted for deposition path planning, which will be concurrently optimized for the best material anisotropy distribution. Therefore, what will be presented in this paper is a novel combination of structural topological design and process planning to derive the optimal hybrid remanufacturing strategy. This is a very novel trial and we have performed experiments to verify its effectiveness.

Closed-loop supply chain models with product take-back and hybrid remanufacturing under technology licensing

The economical and environmental benefits of remanufacturing have been widely recognized in literature and practical life. In this paper, we consider a closed-loop supply chain consisting of a manufacturer, a distributor and a third party, who are engaged in producing remanufactured products. Additionally, the manufacturer as the channel leader tends to cooperate with the distributor and the third party by technology licensing. Specifically, we develop three hybrid remanufacturing models: (1) the manufacturer collects and remanufactures used products by herself (Model M), (2) the manufacturer remanufactures a fraction of used products and licenses the distributor to remanufacture while the distributor collects used products (Model MD), (3) the manufacturer remanufactures a fraction of used products and licenses the third party to remanufacture while the third party collects used products (Model MT). We discuss the impacts of remanufacturing ability on the chain members and environmental sustainability, and also analyze the role of saving unit cost in the remanufacturing process. Moreover, we apply the Stackelberg game to attain the equilibrium strategies from the perspective of chain members' profits. The profit of the manufacturer, the distributor and the third party reaches the most in Model M, Model MD and Model MT, respectively. These results can help achieve an optimal approach of hybrid remanufacturing in a closed-loop supply chain.

A robust optimisation model for hybrid remanufacturing and manufacturing systems under uncertain return quality and market demand

In remanufacturing research, most researchers predominantly emphasised on the recovery of whole product (core) rather than at the component level due to its complexity. In contrast, this paper addresses the challenges to focus on remanufacturing through component recovery, so as to solve production planning problems of hybrid remanufacturing and manufacturing systems. To deal with the uncertainties of quality and quantity of product returns, the processing time of remanufacturing, remanufacturing costs, as well as market demands, a robust optimisation model was developed in this research and a case study was used to evaluate its effectiveness and efficiency. To strengthen this research, a sensitivity analysis of the uncertain parameters and the original equipment manufacturer’s (OEM’s) pricing strategy was also conducted. The research finding shows that the market demand volatility leads to a significant increase in the under fulfilment and a reduction in OEM’s profit. On the other hand, recovery cost reduction, as endogenous cost saving, encourages the OEM to produce more remanufactured products with the increase in market demand. Furthermore, the OEM may risk profit loss if they raise the price of new products, and inversely, they could gain more if the price of remanufactured products is raised.

Substitution in a Hybrid Remanufacturing System

Increasing legislative and societal pressures are requiring manufacturers to operate more sustainably and to take responsibility for the fate of their goods after they have been used by consumers. A hybrid remanufacturing system, in which newly produced and remanufactured used goods are sold on separate markets but also act substitutes for each other, is described and modelled using a semi-Markov decision process. The model provides an optimal policy, which specifies production, remanufacturing and substitution decisions. The model is used to explore the properties of this hybrid remanufacturing system, and in particular, the managerial implications associated with upward and downward substitution.

Production planning for hybrid remanufacturing and manufacturing system with component recovery

In this paper, we address component recovery under the condition of limited resources from the OEM's (Original Equipment Manufacturer's) standpoint. We develop a linear programming model for a hybrid remanufacturing and manufacturing system for production planning problems with deterministic returns. In this paper, a data set from an OEM that both remanufactures and manufactures the products is used to demonstrate the performance of the proposed model. Subsequently, an analysis of the impact of the remanufactured product’s price and the quantity of returns on revenue and total cost will be discussed. We have found that uncertain factors of manufacturing influence the profit and uncertain factors of remanufacturing influence the production planning, such as the rate of the yield on component remanufacturing and the quantity of returns.