Advances in Manufacturing

State of the art of bioimplants manufacturing: part II

Cheng-Wei Kang, Feng-Zhou Fang

2018, 6(2): 137-154. doi:10.1007/s40436-018-0218-9

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The manufacturing of bioimplants not only involves selecting proper biomaterials with satisfactory bulk physicochemical properties, but also requires special treatments on surface chemistry or topography to direct a desired host response. The lifespan of a bioimplant is also critically restricted by its surface properties. Therefore, developing proper surface treatment technologies has become one of the research focuses in biomedical engineering. This paper covers the recent progress of surface treatment of bioimplants from the aspects of coating and topography modification. Pros and cons of various technologies are discussed with the aim of providing the most suitable method to be applied for different biomedical products. Relevant techniques to evaluate wear, corrosion and other surface properties are also reviewed.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0218-9

Comparative study on machinability improvement in hard turning using coated and uncoated carbide inserts: part II modeling, multi-response optimization, tool life, and economic aspects

Ramanuj Kumar, Ashok Kumar Sahoo, Purna Chandra Mishra, Rabin Kumar Das

2018, 6(2): 155-175. doi:10.1007/s40436-018-0214-0

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The present study focused on mathematical modeling, multi response optimization, tool life, and economical analysis in finish hard turning of AISI D2 steel ((55±1) HRC) using CVD-coated carbide (TiN/TiCN/Al₂O₃) and uncoated carbide inserts under dry environmental conditions. Regression methodology and the grey relational approach were implemented for modeling and multi-response optimization, respectively. Comparative economic statistics were carried out for both inserts, and the adequacy of the correlation model was verified. The experimental and predicted values for all responses were very close to each other, implying the significance of the model and indicating that the correlation coefficients were close to unity. The optimal parametric combinations for Al₂O₃ coated carbide were d1-f1-v2 (depth of cut=0.1 mm, feed=0.04 mm/r and cutting speed=108 m/min), and those for the uncoated tool were d1-(0.1 mm)-f1 (0.04 mm/r)-v1 (63 m/min). The observed tool life for the coated carbide insert was 15 times higher than that for the uncoated carbide insert, considering flank wear criteria of 0.3 mm. The chip volume after machining for the coated carbide insert was 26.14 times higher than that of the uncoated carbide insert and could be better utilized for higher material removal rate. Abrasion, diffusion, notching, chipping, and built-up edge have been observed to be the principal wear mechanisms for tool life estimation. Use of the coated carbide tool reduced machining costs by about 3.55 times compared to the use of the uncoated carbide insert, and provided economic benefits in hard turning.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0214-0

Hybrid laser/arc welding of thick high-strength steel in different configurations

M. Mazar Atabaki, N. Yazdian, R. Kovacevic

2018, 6(2): 176-188. doi:10.1007/s40436-017-0193-6

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In this investigation, hybrid laser/arc welding (HLAW) was employed to join 8-mm-thick high-strength quenched and tempered steel (HSQTS) plates in the butt-and T-joint configurations. The influences of welding parameters, such as laser power, welding speed, stand-off distance (SD) between the arc of gas metal arc welding, and the laser heat source on the weld quality and mechanical properties of joints, were studied to obtain non-porous and crack-free fully-penetrated welds. The weld microstructure, crosssection, and mechanical properties were evaluated by an optical microscope, and microhardness and tensile tests. In addition, a finite element model was developed to investigate the thermal history and molten pool geometry of the HLAW process to join the HSQTS. The numerical study demonstrated that the SD had a paramount role in good synergy between the heat sources and the stability of the keyhole. For the butt-joint configuration, the results showed that, at a higher welding speed (35 mm/s) and optimum SD between the arc and laser, a fully-penetrated sound weld could be achieved. A non-porous weld in the T-joint configuration was obtained at a lower welding speed (10 mm/s). Microstructural evaluations indicated that the formation of residual austenite and the continuous network of martensitic structure along the grain boundary through the heat affected zone were the primary reasons of the softening behavior of this area. This was confirmed by the sharp hardness reduction and failure behavior of the tensile coupons in this area.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0193-6

Fine equiaxed dendritic structure of a medium carbon steel cast using pulsed magneto-oscillation melt treatment

Jie Sun, Cheng Sheng, Ding-Pu Wang, Jing Zhao, Yun-Hu Zhang, Hong-Gang Zhong, Gui Wang, Qi-jie Zhai

2018, 6(2): 189-194. doi:10.1007/s40436-017-0206-5

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The application of a pulsed magneto-oscillation (PMO) technique during the solidification of a commercial high melting point medium carbon steel ingot (φ140 mm 9 450 mm) produced fully equiaxed grains in the cast ingot, indicating that the PMO process significantly promotes heterogeneous nucleation near the solid-liquid interface. The vigorous convection induced by PMO forced the partly solidified grains to move from the solid-liquid interface and became randomly distributed throughout the melt, which resulted in the formation of uniformly sized equiaxed dendrites throughout the whole ingot. Building on the developed nucleation mechanism and a flow field simulation of pure aluminum, a PMO-induced grain refinement model for steel is proposed.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0206-5

In-situ stitching interferometric test system for large plano optics

Xin Wu, Ying-Jie Yu, Ke-Bing Mou, Wei-Rong Wang

2018, 6(2): 195-203. doi:10.1007/s40436-018-0220-2

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In-situ testing is an ideal technology for improving the precision and efficiency of fabrication. We developed an in-situ subaperture stitching interferometric test system for large plano optics in the workshop environment with high precision and satisfactory repeatability. In this paper, we provide a brief account of this system and the principle of insitu subaperture stitching measurement. Several validation tests are presented, which demonstrate that the developed system is capable of realizing in-situ testing. The size of optical flats can be measured is up to 420 mm×780 mm, and repeatability is smaller than 0.03λ. The paper also discusses the necessary requirements for a suitable workshop environment for ensuring that the tests are stable and reliable.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0220-2

3D numerical analysis of drilling process: heat, wear, and built-up edge

Mohammad Lotfi, Saeid Amini, Ihsan Yaseen Al-Awady

2018, 6(2): 204-214. doi:10.1007/s40436-018-0223-z

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In this study, a 3D finite element model is developed to investigate the drilling process of AISI 1045 steel, and particularly, the heat and wear on the drill faces. To model drill wear, a modified Usui flank wear rate is used. Experiments are used for the verification of the simulated model and the evaluation of the surface roughness and built-up edge. A comparison of the predicted and experimental thrust forces and flank wear rates revealed that the predicted values had low errors and were in good agreement with the experimental values, which showed the utility of the developed model for further analysis. Accordingly, a heat analysis indicated that approximately half the generated heat in the cutting zone was conducted to the drill bit. Furthermore, material adhesion occurred in localized heat areas to a great extent, thus resulting in wear acceleration. A maximum flank wear rate of 0.026 1 mm/s was observed when the rotary speed and feed rate were at the lowest and highest levels, respectively. In the reverse cutting condition, a minimum flank wear rate of 0.016 8 mm/s was observed.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-018-0223-z

Effect of machining parameters on edge-chipping during drilling of glass using grinding-aided electrochemical discharge machining (G-ECDM)

V. G. Ladeesh, R. Manu

2018, 6(2): 215-224. doi:10.1007/s40436-017-0194-5

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The problem of eliminating edge-chipping at the entrance and exit of the hole while drilling brittle materials is still a challenging task in different industries. Grindingaided electrochemical discharge machining (G-ECDM) is a promising technology for drilling advanced hard-to-machine ceramics, glass, composites, and other brittle materials. Edge-chipping at the entrance of the hole can be fully eliminated by optimizing the machining parameters of G-ECDM. However, edge-chipping at the exit of the hole is difficult to eliminate during the drilling of ceramics and glass. This investigation suggests some practical ways to reduce edge-chipping at the exit of the hole. For this purpose, a three-dimensional finite element model was developed, and a coupled field analysis was conducted to study the effect of four parameters, i.e., cutting depth, support length, applied voltage, and pulse-on time, on the maximum normal stress in the region where the edgechipping initiates. The model is capable of predicting the edge-chipping thickness, and the results predicted by the model are in close agreement with the experiment results. This investigation recommends the use of a low voltage and low pulse-on time at the hole entrance and exit when applying G-ECDM to reduce the edge-chipping thickness. Moreover, the use of a full rigid support in the form of a base plate or sacrificial plate beneath the workpiece can postpone the initiation of chipping by providing support when the tool reaches the bottom layer of the workpiece, thereby reducing the edge-chipping thickness.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0194-5

Evaluation and analysis of cutting speed, wire wear ratio, and dimensional deviation of wire electric discharge machining of super alloy Udimet-L605 using support vector machine and grey relational analysis

Somvir Singh Nain, Dixit Garg, Sanjeev Kumar

2018, 6(2): 225-246. doi:10.1007/s40436-017-0192-7

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The current study investigates the behavior of wire electric discharge machining (WEDM) of the super alloy Udimet-L605 by employing sophisticated machine learning approaches.The experimental work was designed on the basis of the Taguchi orthogonal L27 array,considering six explanatory variables and evaluating their influences on the cutting speed,wire wear ratio (WWR),and dimensional deviation (DD).A support vector machine (SVM) algorithm using a normalized poly-kernel and a radial-basis flow kernel is recommended for modeling the wire electric discharge machining process.The grey relational analysis (GRA) approach was utilized to obtain the optimal combination of process variables simultaneously, providing the desirable outcome for the cutting speed, WWR,and DD.Scanning electron microscope and energy dispersive X-ray analyses of the samples were performed for the confirmation of the results.An SVM based on the radial-basis kernel model dominated the normalized polykernel model.The optimal combination of process variables for a mutually desirable outcome for the cutting speed,WWR,and DD was determined as T_on1,T_off2,I_P1, WT3,SV1,and WF3.The pulse-on time is the significant variable influencing the cutting speed,WWR,and DD.The largest percentage of copper (8.66%) was observed at the highest cutting speed setting of the machine compared to 7.05% of copper at the low cutting speed setting of the machine.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0192-7

Calculation of phase equilibria in Al-Fe-Mn ternary system involving three new ternary intermetallic compounds

Lu-Hai Zhou, Zhu Li, Shu-Sen Wang, Ren-Min Hu, Shi-Hua Wang, Zi-Wei Qin, Xiong-Gang Lu, Chong-He Li

2018, 6(2): 247-257. doi:10.1007/s40436-017-0199-0

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In this study, the Al-Fe-Mn ternary system is reassessed by the CALPHAD method. Three new ternary intermetallic compounds are initially described and a reasonable and self-consistent set of thermodynamic parameters are established to describe this system. The 973 K, 1 073 K, 1 173 K, 1 273 K, 1 373 K, and 1 473 K isothermal sections and the 1 073 K, 1 013 K, 968 K and 913 K isothermal sections at the Al corner as well as the liquidus projection at the Al corner are calculated. It is shown that the calculated results are in good agreement with almost all of the experimental results previously reported.

The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-017-0199-0

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