Advances in Manufacturing

In vitro evaluation of artificial joints: a comprehensive review

Gang Shen, Ju-Fan Zhang, Feng-Zhou Fang

2019, 7(1): 1-14. doi:10.1007/s40436-018-00244-z

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Development of artificial joints is a great progress for joint replacement operations of human being, but the short longevity of prostheses has concerned both industries and researchers since the advent of modern implants. Thus, continuous improvements have been made alongside the clinical applications. The methodologies to inspect the potential properties of new designs have also seen many advances. The test machines have evolved from easy pin-on-disk configuration to the modern joint simulator. Besides, various wear traces provided by testing machines are investigated greatly, and multi-directional files are recommended as motion profiles for in vitro testing. The typical testing parameters, like sliding speed or loading profile, are discussed in this article, and their working mechanisms are described in detail. Meanwhile, the calf or bovine serum has been regarded as the gold standard for testing lubricant, and the future trend of fluid will be focused on investigating the effects of lubricant composites on the tribological properties. Hard particles and proteins are discussed as well, and their effects on the wear mechanisms are the focus. Finally, various approaches to measure the wear rate, wear factor and the thickness of lubricant film are presented, and suggestions are given for the development in future.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-00244-z.pdf

Dynamic interplay between dislocations and precipitates in creep aging of an Al-Zn-Mg-Cu alloy

Heng Li, Tian-Jun Bian, Chao Lei, Gao-Wei Zheng, Yu-Fei Wang

2019, 7(1): 15-29. doi:10.1007/s40436-018-0240-y

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Creep age forming (CAF) is an advanced forming technology used for manufacturing large complex integrated panel components. However, in creep aging (CA), unlike in sole creep or aging procedure, the dislocation movement and the precipitation process occur simultaneously, leading to difficulty in understanding of the dynamic interplay between these two phenomena. In this work, taking 7050 Al alloy, a typical Al-Zn-Mg-Cu alloy, as the test material, an experimental scheme combining pre-deformation, artificial aging (AA), and tensile/compressive CA is designed to decouple and reveal the dynamic interaction mechanism of both phenomena. From AA experiments, the static interaction between dislocations and precipitates is studied, and then their dynamic interactions in CA and each evolution are comparatively investigated. The research shows that both total strain and strain rate increase with the increase in pre-deformation in tensile and compressive CA. However, the total creep strain in compressive CA is larger than that in tensile CA. In additional, the more the dislocations are induced, the sparser and more heterogeneous the overall distribution of precipitates becomes. For dynamic interplay, in the first stage of CA (I), under thermal-mechanical loading, the GP zones and η' phases gradually nucleate and grow, while the effect of dislocation multiplication is dominant compared with dislocation annihilation, leading to an increase in total dislocation density. Soon, the dislocation movement is gradually hindered by tangling, pile-up, and the precipitates that have grown on the dislocation lines, this decreases the mobile dislocation density and results in a significant decrease in creep rate. In the second stage (Ⅱ), the precipitates grow further, especially those lying on the dislocation lines; the effects of pinning and hindrance are enhanced until the dislocation multiplication and annihilation reach a dynamic equilibrium, and the total and mobile dislocation densities tend to be roughly unchanged, thus, the creep rate remains relatively constant in this stage.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-0240-y.pdf

Physical-based constitutive model considering the microstructure evolution during hot working of AZ80 magnesium alloy

Ze-Xing Su, Chao-Yang Sun, Ming-Wang Fu, Ling-Yun Qian

2019, 7(1): 30-41. doi:10.1007/s40436-018-0243-8

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A physical-based constitutive model was developed to model the viscoplastic flow behavior and microstructure evolution of AZ80 magnesium alloy during the hot working process. The competing deformation mechanisms, including work hardening, dynamic recovery, and dynamic recrystallization, in an isothermal compression environment were considered in the model. The internal state variables, including the normalized dislocation density and recrystallized volume fraction, were incorporated into the model to articulate the microstructure evolution during hot deformation. The kinetic condition critical for dynamic recrystallization, considering the effects of the deformation temperature and strain rate, was obtained by employing both the Poliak-Jonas criterion and Zener-Hollomon parameter. Microstructure observations indicate that the recrystallized volume fraction increases with decreasing Z parameter at constant strain, which is consistent with the predicted kinetics model. Based on the developed model, a good correlation was also obtained between the predicted and experimental flow stress. The results indicate a good predictability of the model in describing the hot deformation behavior and microstructure evolution of AZ80 magnesium alloy.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-0243-8.pdf

Reduction of die roll height in duplex gears through a sheet-bulk metal forming method

Xiao-Long Sun, Xin-Cun Zhuang, Feng-Chun Yang, Zhen Zhao

2019, 7(1): 42-51. doi:10.1007/s40436-018-00245-y

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In the existing shearing processes for fabricating parts such as duplex gears, die roll is difficult to avoid. Accordingly, a method based on sheet-bulk metal forming for fabricating a duplex gear with extremely small die roll in one stroke is proposed in the current work. The process could be divided into three stages according to the forming features:upsetting and shearing stage, lateral extrusion stage, and local filling stage. The die roll appeared in the shearing stage, which could be reduced in the subsequent extrusion and local filling stages. To reveal the underground mechanism, material flows under two situations, as a key factor to influence the forming quality, were compared and investigated. The results revealed that by controlling material flow, one could avoid the defects and reduce the die roll.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-00245-y.pdf

Research on the microstructure evolution of Ni-based superalloy cylindrical parts during hot power spinning

Qin-Xiang Xia, Jin-Chuan Long, Ning-Yuan Zhu, Gang-Feng Xiao

2019, 7(1): 52-63. doi:10.1007/s40436-018-0242-9

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To predict the microstructure evolution and reveal the forming mechanism of Ni-based superalloy cylindrical parts during hot power spinning, a finite element method (FEM) model of deformation-heat transfermicrostructure evolution was established using MSC.Marc software. A numerical simulation was then conducted based on the secondary development of user subroutines, to investigate evolution of the microstructure of a Haynes 230 alloy cylindrical part during hot power spinning. The volume fraction of dynamic recrystallization (DRX) and the grain size of Haynes 230 alloy cylindrical parts during hot power spinning were analyzed. The results showed that the DRX of the spun workpiece was more obvious with an increase in the forming temperature, T, and the total thinning ratio of wall thickness, Ψ_t. Furthermore, the complete DRX microstructure with fine and uniform grains was obtained when T ≥ 1 100℃ and Ψ_t ≥ 56%, but the grain size of the spun workpiece decreased slightly with an increase in the roller feed rate, f. The experimental results conformed well with simulation results.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-0242-9.pdf

Tool-path generation for industrial robotic surface-based application

He Lyu, Yue Liu, Jiao-Yang Guo, He-Ming Zhang, Ze-Xiang Li

2019, 7(1): 64-72. doi:10.1007/s40436-018-00246-x

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Industrial robots are widely used in various applications such as machining, painting, and welding. There is a pressing need for a fast and straightforward robot programming method, especially for surface-based tasks. At present, these tasks are time-consuming and expensive, and it requires an experienced and skilled operator to program the robot for a specific task. Hence, it is essential to automate the tool-path generation in order to eliminate the manual planning. This challenging research has attracted great attention from both industry and academia. In this paper, a tool-path generation method based on a mesh model is introduced. The bounding box tree and kdtree are adopted in the algorithm to derive the tool path. In addition, the algorithm is integrated into an offline robot programming system offering a comprehensive solution for robot modeling, simulation, as well as tool-path generation. Finally, a milling experiment is performed by creating tool paths on the surface thereby demonstrating the effectiveness of the system.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-00246-x.pdf

Cladding of aluminum alloy 6061-T6 to mild steel by an electromagnetic tube bulging process: finite element modeling

Zhi-Song Fan, Su-Ting Huang, Jiang-Hua Deng

2019, 7(1): 73-83. doi:10.1007/s40436-018-00247-w

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Bimetal tubes have useful applications in various industries where service conditions demand more different requirements in the tube core than its outside surface. The recent use of electromagnetic forces to deform or join metallic workpieces at high speeds has undergone rapid growth for materials processing. However, to date, no sufficient systematic understanding of the underlying principles of a subsequent high-speed electromagnetic tube bulging process to manufacture bimetal tubes has been gained. In this work, magnetic pulse cladding of Al/Fe clad bimetal tubes was analyzed by finite element modeling (FEM) using ANSYS software. The validity of FEM analyses was first confirmed by experiments in terms of the deformed shape. Second, the effect of cladding parameters (such as axial feeding being the dominant factor in the multi-step process) on the bulging and thinning behavior of the Al clad tube was presented in detail. Both the numerical simulation and experimental results show that no more than 70% of the bulging-coil length is an appropriate amount for the feeding length to prevent defects from being introduced by non-uniform deformation in the transition zone of the Al clad tube. The distributions of the magnetic flux line, magnetic force, and plastic strain in different cladding steps were then analyzed. It was concluded that during the multi-step cladding process, there was an uneven distribution of the magnetic field force along the transition zone. Consequently, inharmonious plastic deformation behavior occurs, which results in a limited acceleration of the transition zone to a certain impact velocity.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-00247-w.pdf

Microstructural evolution of a steam-turbine rotor subjected to a water-quenching process: numerical simulation and experimental verification

Chuan Wu, Qing-Ling Meng

2019, 7(1): 84-104. doi:10.1007/s40436-018-00248-9

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Cr-Ni-Mo-V steam-turbine rotors have been widely used as key components in power plants. In this study, a coupled thermomechano-metallurgical model was proposed to simulate the phase transformation and transformation-induced plasticity (TRIP) of a 30Cr2Ni4MoV steam-turbine rotor during a water-quenching process, which was solved using a user defined material mechanical behavior (UMAT) subroutine in ABAQUS. The thermal dilation, heat generation from plastic work, transformation latent heat, phase transformation kinetics, and TRIP were considered in the model. The thermomechanical portion of the model was used to predict the evolution of temperature, strain, and residual stress in the rotor. The phase transformation that occurred during the quenching process was considered. Constitutive models of phase transformations (austenite to pearlite, austenite to bainite, and austenite to martensite) and TRIP were developed. Experimental data were adopted and compared with the predicted results to verify the accuracy of the model. This demonstrates that the model is reliable and accurate. Then, the model was utilized to predict the temperature variation, dimensional change, minimum austenitization time, residual stress, TRIP, and volume fractions of each phase. It is concluded that this model can be a useful computational tool in the design of heat-treatment routines of steam-turbine rotors.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-00248-9.pdf

Forming the transverse inner rib of a curved generatrix part through power spinning

Hong-Rui Zhang, Mei Zhan, Jing Guo, Xian-Xian Wang, Peng-Fei Gao, Fei Ma

2019, 7(1): 105-115. doi:10.1007/s40436-018-0241-x

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How to form high-quality transverse inner ribs through power spinning is a key issue for complicated integrated curved generatrix parts with transverse inner ribs. In this study, the forming characteristics and laws during the power spinning process were investigated using a finite element simulation based on the orthogonal design method. The results show that the transverse inner rib distributes homogeneously along the circumferential direction but inhomogeneously along the generatrix direction. Depressions occur easily in the middle zone of the rib (MZR). The roller nose radius is the most significant parameter of the MZR underfill degree. A larger roller nose radius is helpful to decrease the MZR underfill degree. Furthermore, the preformed billet thickness also plays a vital role in the underfill degree of the front zone of the rib and the back zone of the rib, as well as the depression degree of the outer surface of the rib. By combining the ribfilling characteristics and laws, the optimized forming process window for obtaining high-quality inner ribs was obtained by regression analysis, thus laying a basis for improving the forming quality of curved generatrix parts with transverse inner ribs in power spinning.

The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-0241-x.pdf

Retraction Note: Effects of roller burnishing process parameters on surface roughness of A356/5% SiC composite using response surface methodology

Shashi Prakash Dwivedi, Satpal Sharma, Raghvendra Kumar Mishra

2019, 7(1): 116-116. doi:10.1007/s40436-018-0232-y

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The full text can be downloaded at https://link.springer.com/content/pdf/10.1007%2Fs40436-018-0232-y.pdf

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