Junzhou Yang, Jianjun Wu, Qianwen Zhang, Yinxiang Ren, Han Ruolan and Kaiwei Wang
With the discussion on the linear relationship of determined material parameters, this study aims to propose a new method to analyze the deformation mechanism.
Abstract
Purpose
With the discussion on the linear relationship of determined material parameters, this study aims to propose a new method to analyze the deformation mechanism.
Design/methodology/approach
A modified constitutive model based on the hyperbolic sine Arrhenius equation has been established, which is applied to describe the flow behavior of Ti-6Al-4V alloy during the superplastic forming (SPF).
Findings
The modified constitutive model in this work has a good ability to describe the flow behavior for Ti-6Al-4V in SPF. Besides, a deformation map of titanium material is obtained based on the parameters. As the supplement, finite element models of high-temperature tensile tests are carried out as the application of the constitutive model.
Originality/value
The relationship between constitutive model parameters and forming mechanism is established, which is a new angle in rheological behavior research and constitutive model analysis.
Details
Keywords
Long Zhang, Kaiwei Zhang and Dejun Kong
The purpose of this study to investigate the high temperature tribological performances of CrN and CrAlN coatings on AISI H13 steel, which was beneficial to improve the wear…
Abstract
Purpose
The purpose of this study to investigate the high temperature tribological performances of CrN and CrAlN coatings on AISI H13 steel, which was beneficial to improve the wear resistance of hot work molds.
Design/methodology/approach
Arc ion plating was used to deposit the CrN and CrAlN coatings on AISI H13 steel, and the tribological performances of CrN and CrAlN coatings were evaluated using a ball-on-plate wear tester.
Findings
The average coefficients of friction and wear rate of CrAlN coating in the normal wear period are 0.33 and 5.34 × 10–9 mm3·N–1·mm–1, respectively, which are lower than those of CrN coating, exhibiting that the outstanding friction reduction. The formations of Cr and Al oxides during the wear process are the main factor in enhancing the tribological performance of CrAlN coating.
Originality/value
CrN and CrAlN coatings were applied for hot work molds, and their tribological performances were comparatively investigated.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2024-0359/
Details
Keywords
Anagi Balachandra, Roz-Ud-Din Nassar and Parviz Soroushian
This study aims to report the development and experimental evaluation of three innovative corrosion-resistant modified epoxy coatings, namely, nanocomposite/toughened…
Abstract
Purpose
This study aims to report the development and experimental evaluation of three innovative corrosion-resistant modified epoxy coatings, namely, nanocomposite/toughened, self-healing and hybrid epoxy coatings, for application on steel substrates.
Design/methodology/approach
The corrosion resistance of these coatings was evaluated in a highly corrosive environment of salt fog spray for 2,500 h of exposure. Electrochemical impedance spectroscopy (EIS) measurements in sustained exposure to NaCl in a saturated Ca(OH)2 solution, rust creepage measurements at the location of scribe formed in the coatings and adhesion strength test were used to assess the performance of the innovative coatings. Commercially available marine-grade protective epoxy coatings were used as the reference coatings.
Findings
The test results showed that the modified epoxy coatings exhibited excellent corrosion resistance when exposed to an aggressive environment for extended periods. The EIS measurements, rust creepage measurements, pull-off strength and visual appearance of the aged modified–epoxy–coated specimens confirmed the enhanced corrosion resistance of the modified epoxy coatings.
Originality/value
Among the three types of modified coatings, the hybrid epoxy coating stands out to be the best performer.
Details
Keywords
Redha Benachour, Saïda Latreche, Mohamed El Hadi Latreche and Christian Gontrand
The present work aims to explain how the nonlinear average model can be used in power electronic integration design as a behavioral model.
Abstract
Purpose
The present work aims to explain how the nonlinear average model can be used in power electronic integration design as a behavioral model.
Design/methodology/approach
The nonlinear average model is used in power electronic integration design as a behavioral model, where it is applied to a voltage source inverter based on IGBTs. This model was chosen because it takes into account the nonlinearity of the power semiconductor components and the wiring circuit effects, which can be formalized by the virtual delay concept. In addition, the nonlinear average model cannot distinguish between slow and quick variables and this is an important feature of the model convergence.
Findings
The paper studies extensively the construction of the nonlinear average model algorithm theoretically. Detailed explanations of the application of this model to voltage source inverter design are provided. The study demonstrates how this model illustrates the effect of the nonlinearity of the power semiconductor components' characteristics on dynamic electrical quantities. It also predicts the effects due to wiring in the inverter circuit.
Research limitations/implications
More simulations and experimental analysis are still necessary to improve the model's accuracy, by using other static characteristic approaches, and to validate the applicability of the model to different converter topologies.
Practical implications
The paper formulates a simple nonlinear average model algorithm, discussing each step. This model was described by VHDL‐AMS. On the one hand, it will assist theoretical and practical research on different topologies of power electronic converters, particularly in power integration systems design such as the integrated power electronics modules (IPEM). On the other hand, it will give designers a more precise behavioral model with a simpler design process.
Originality/value
The nonlinear average model used in power electronic integration design as behavioral model is a novel approach. This model reduces computational costs significantly, takes physical effects into account and is easy to implement.