scholarly journals Reverse identification of constitutive parameters of Inconel 718 alloy based on analytical model and thermo-mechanical loads analysis of machined surface

Author(s):  
Pengfei Tian ◽  
Lin He ◽  
Tao Zhou ◽  
Feilong Du ◽  
Zichuan Zou ◽  
...  
2019 ◽  
Vol 9 (4) ◽  
pp. 690 ◽  
Author(s):  
Dengyong Wang ◽  
Bin He ◽  
Wenjian Cao

Electrochemical machining (ECM) is a cost-effective method for the machining of difficult-to-cut Inconel 718 superalloy. However, the machining accuracy of ECM is still limited by the poor localization effect due to the existence of stray corrosion. In this paper, a mixed solution of neutral NaNO3 and alkaline NaOH is used to improve the localization effect during ECM of Inconel 718. The potentiodynamic polarization curves and current efficiencies for metal dissolution are measured, and the micro morphologies are examined. The results show that the use of an alkaline solution can promote the formation of a compact passive film on the surface of Inconel 718. ECM tests with cylindrical electrodes are specially designed to verify the effect of alkaline solution on the localization of anodic dissolution. The experimental results indicated that the stray corrosion of the non-machined surface of Inconel 718 alloy can be effectively eliminated by using a mixed solution of NaNO3 and NaOH. The surface roughness of the non-machined area can be noticeably improved.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7524
Author(s):  
Bartłomiej Krawczyk ◽  
Piotr Szablewski ◽  
Stanisław Legutko ◽  
Krzysztof Smak ◽  
Bartosz Gapiński

This paper presents the results of investigation that was performed on shafts composed of Inconel 718. Tests were performed in dry and wet conditions. Cutting parameters, such as feed and depth of cut, were constant. The cutting speed was changed. The investigation was performed for various shaft shapes: cylindrical, taper 30°, taper 45°, and sphere. For that reason, the value of the angle between the machined surface and the cutting edge changed. The lowest values of the roughness parameters, Ra and Rz, were obtained for a larger value of the angle between the machined surface and cutting edge. The investigation showed that cutting speed, machining conditions (dry and wet machining), and the variable angle between the machined surface and the cutting edge influenced the surface roughness. Application of a higher cutting speed resulted in lower roughness values. Lower values of roughness parameters were obtained by wet machining.


2011 ◽  
Vol 410 ◽  
pp. 245-248 ◽  
Author(s):  
Naveen Beri ◽  
S. Maheshwari ◽  
C. Sharma

In recent years, researchers have reported powder metallurgy processed electrodes as alternative tooling for electrical discharge machining (EDM). The present experimental study evaluates the quality of machined surface during electrical discharge machining (EDM) of Inconel 718 alloy steel with powder metallurgy (PM) processed electrodes. The investigated process parameters were polarity, electrode type, peek current, pulse on time, duty cycle, gap voltage, retract distance and flushing pressure. The surface quality was measured in terms of surface roughness (Ra). An orthogonal array L36 (21X 37) based on Taguchi methodology was applied to plan and design experiments. Experimental data was statistically analyzed using analysis of variance (ANOVA) and optimum condition was achieved for evaluation criteria. It was concluded that polarity, electrode type, peek current, have significant effect on surface quality and minimum Ra is obtained with CuW2080 electrode at minimum current and negative polarity. Deposition of tungsten with CuW2080 (80%W 20%Cu) electrode was confirmed by energy dispersion spectrum (EDS) of the machined surface.


2021 ◽  
Vol 9 (2) ◽  
pp. 294-312
Author(s):  
Md Ehsan Asgar ◽  
Ajay Kumar Singh Singholi

In today’s competitive modern manufacturing sectors, there is a vital need of utter precision and rigorous processing using various manufacturing approaches that directly influences the cost and processing duration of mechanized materials in addition to the consistency of the finished products. Therefore, it’s essential to figure out the required output by adjusting the control factors of any machining techniques which resulted in optimal values of the desired outcome. In this study, machining evaluation and process optimization is carried out on volumetric extraction of material namely material removal rate (MRR), kerf obtained during the machining (KW) and surface roughness (SR) of Inconel 718 superalloy during CNC controlled wire- electrical discharge machining. Four controllable factors- pulse interval, wire speed, pulse duration and peak current are considered to investigate the influence on performance measures. Taguchi's L16 has been used to construct the set of experiments before physical experimental runs and most influencing factors have been evaluated using ANOVA. SEM images and EDXS analysis have been resorted to examine the morphology of Inconel 718. These findings assist in identifying the topography of the machined surface. Further, the optimum integration has been obtained for the best yield and recorded using grey relational analysis integrated with Taguchi’s technique (T-GRA). The unfamiliarity of the work is based on consideration of zinc coated thin wire electrode and Taguchi-Grey combined approach of modelling with four levels of experimental design.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 876 ◽  
Author(s):  
Sapam Ningthemba Singh ◽  
Sohini Chowdhury ◽  
Yadaiah Nirsanametla ◽  
Anil Kumar Deepati ◽  
Chander Prakash ◽  
...  

Investigation of the selective laser melting (SLM) process, using finite element method, to understand the influences of laser power and scanning speed on the heat flow and melt-pool dimensions is a challenging task. Most of the existing studies are focused on the study of thin layer thickness and comparative study of same materials under different manufacturing conditions. The present work is focused on comparative analysis of thermal cycles and complex melt-pool behavior of a high layer thickness multi-layer laser additive manufacturing (LAM) of pure Titanium (Ti) and Inconel 718. A transient 3D finite-element model is developed to perform a quantitative comparative study on two materials to examine the temperature distribution and disparities in melt-pool behaviours under similar processing conditions. It is observed that the layers are properly melted and sintered for the considered process parameters. The temperature and melt-pool increases as laser power move in the same layer and when new layers are added. The same is observed when the laser power increases, and opposite is observed for increasing scanning speed while keeping other parameters constant. It is also found that Inconel 718 alloy has a higher maximum temperature than Ti material for the same process parameter and hence higher melt-pool dimensions.


Author(s):  
Yanbing Tang ◽  
Xinwang Shen ◽  
Yanxin Qiao ◽  
Lanlan Yang ◽  
Jian Chen ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1001
Author(s):  
Zongxian Song ◽  
Wenbin Gao ◽  
Dongpo Wang ◽  
Zhisheng Wu ◽  
Meifang Yan ◽  
...  

This study investigates the very-high-cycle fatigue (VHCF) behavior at elevated temperature (650 °C) of the Inconel 718 alloy fabricated by selective laser melting (SLM). The results are compared with those of the wrought alloy. Large columnar grain with a cellular structure in the grain interior and Laves/δ phases precipitated along the grain boundaries were exhibited in the SLM alloy, while fine equiaxed grains were present in the wrought alloy. The elevated temperature had a minor effect on the fatigue resistance in the regime below 108 cycles for the SLM alloy but significantly reduced the fatigue strength in the VHCF regime above 108 cycles. Both the SLM and wrought specimens exhibited similar fatigue resistance in the fatigue life regime of fewer than 107–108 cycles at elevated temperature, and the surface initiation mechanism was dominant in both alloys. In a VHCF regime above 107–108 cycles at elevated temperature, the wrought material exhibited slightly better fatigue resistance than the SLM alloy. All fatigue cracks are initiated from the internal defects or the microstructure discontinuities. The precipitation of Laves and δ phases is examined after fatigue tests at high temperatures, and the effect of microstructure on the formation and the propagation of the microstructural small cracks is also discussed.


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