Simulation of Solidification of a 19 Inch Diameter, Double Length Steel Ingot

Author(s):  
Steven L. Dedmon ◽  
Shelly Dutler ◽  
James Pilch ◽  
Jay Galbraith

Identifying the process variables that are important to ensuring the production of high quality ingots intended to make railway wheels and axles can be done through costly experimentation, or by numerical simulations. Using MAGMASOFT® software, we created a base model. The base model was validated in three different ways, using results from production to compare against the simulation. Process parameters were then varied to determine if the changes were beneficial or detrimental to conditions such as porosity, pipe and segregation.

2007 ◽  
Vol 353-358 ◽  
pp. 1935-1938 ◽  
Author(s):  
Yasuhiro Yamazaki ◽  
T. Kinebuchi ◽  
H. Fukanuma ◽  
N. Ohno ◽  
K. Kaise

Thermal barrier coatings (TBCs), that reduce the temperature in the underlying substrate material, are an essential requirement for the hot section components of industrial gas turbines. Recently, in order to take full advantage of the potential of the TBC systems, experimental and analytical investigations in TBC systems have been performed. However there is a little information on the deformation behavior of the top coating. In addition, the effects of the thermal exposure and the process parameters on the mechanical properties of the top coating have never been clarified. From these backgrounds, the effects of the process variables in APS and the thermal exposure on the mechanical properties were investigated in order to optimize the APS process of top coatings. The experimental results indicated that the mechanical properties of the APS-TBC, i.e. the tensile strength and the elastic modulus, were significantly changed by the process variables and the long term thermal exposure. The microstructural investigation was also carried out and the relationship between the mechanical properties and the porosity was discussed.


2016 ◽  
Vol 874 ◽  
pp. 291-296 ◽  
Author(s):  
Lin Li ◽  
Jun Wang ◽  
Huai Zhong Li

An experimental study is reported to characterise the femtosecond (FS) laser grooving process for Germanium (Ge) substrates. The effects of process parameters, including laser fluence, pulse repetition rate and scan speed, on the groove characteristics, material removal rate (MRR) and heat affected zone (HAZ) size are discussed. It is shown that with properly selected process parameters, high quality micro-grooves can be obtained on Ge wafers. Recommendations are finally made on the selection of the most appropriate process parameters for FS micro-grooving of Ge substrates.


2014 ◽  
Vol 609-610 ◽  
pp. 64-67
Author(s):  
Xiao Ni Ma ◽  
Li Hua Zhang ◽  
Li Xue Zheng ◽  
Zhan Hua Yang ◽  
Qing Gao ◽  
...  

Anodic spark deposition (ASD) is a novel technique to deposit bioceramic films on the surface of titanium (Ti) and its alloys, and the films prepared with nano/micro scale pores are characterized by high-quality performance for dental implant. Among the process parameters, electrolyte provides a leading role owing to its vital influence not only on the films chemistry but also on the electrical conductivity of the circuit, which affects the film properties. In this study, titania porous films were synthesized by ASD and the effect of electrolytic temperature on microstructure and chemical composition of the films was studied. The results show that the electrolytic temperature could significantly influence the surface topography, thickness and chemical composition of the oxidation films produced by ASD and, therefore, determined the layered hydroapatite (HA) deposition as the other process parameters were fixed.


2013 ◽  
Vol 797 ◽  
pp. 444-449 ◽  
Author(s):  
Kai Ping Feng ◽  
Zhao Zhong Zhou ◽  
Bing Hai Lv ◽  
Ju Long Yuan

This paper represents a dual-plane polishing method for ceramics ball. Compared with traditional ball polishing method, its upper and lower plate are all flat and easy to use soft pad to polish, so it can largely reduce the surface mechanical damage and obtain high quality processing surface. This paper analyzes surface polishing trajectory by calculation and simulation to test the polishing trajectory uniformity. A mathematics model of polishing process is established to disintegrate the process of a balls movement. Experiment is operated in dual-plane planetary polishing machine. The result shows that perfect polishing surface and spherical error can be obtained under the proper process parameters, the surface roughness achieves 4nm and the spherical error can reach 0.217μm.


Author(s):  
Shantanu Shahane ◽  
Soham Mujumdar ◽  
Namjung Kim ◽  
Pikee Priya ◽  
Narayana Aluru ◽  
...  

Die casting is a type of metal casting in which liquid metal is solidified in a reusable die. In such a complex process, measuring and controlling the process parameters is difficult. Conventional deterministic simulations are insufficient to completely estimate the effect of stochastic variation in the process parameters on product quality. In this research, a framework to simulate the effect of stochastic variation together with verification, validation, and uncertainty quantification is proposed. This framework includes high-speed numerical simulations of solidification, micro-structure and mechanical properties prediction models along with experimental inputs for calibration and validation. Both experimental data and stochastic variation in process parameters with numerical modeling are employed thus enhancing the utility of traditional numerical simulations used in die casting to have a better prediction of product quality. Although the framework is being developed and applied to die casting, it can be generalized to any manufacturing process or other engineering problems as well.


Author(s):  
Xiaolan Han ◽  
Zhanfeng Liu ◽  
Yazhou Feng

In the deep-hole boring process on pure niobium tube, there exist some problems including serious tool wear, tough chips, and poor surface quality. In order to bore high-quality deep holes on rolled niobium tube, the cutting tool structure and boring process parameters suitable for machining rolled niobium tube were designed and two experimental schemes were proposed. The results showed that the geometric parameters of the cutting tool and process parameters have important influences on the tool wear, chip morphologies, hole-axis deflection, and hole surface roughness. By adjusting the geometric parameters of the cutting tool and boring process parameters, reasonable geometric parameters of the cutting tool and boring process parameters were obtained.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2052 ◽  
Author(s):  
Liang Wei ◽  
Chengkun Liu ◽  
Xue Mao ◽  
Jie Dong ◽  
Wei Fan ◽  
...  

There is a great limitation to improving the quality and productivity of nanofibers through the conventional single-needle method. Using needleless electrospinning technology to generate multiple jets and enhance the productivity of nanofibers has attracted lots of interest for many years. This study develops a novel linear flume spinneret to fabricate nanofibers. Multiple jets with two rows can be formed simultaneously on the surface of the spinneret. The solution concentration has a significant impact on the average nanofiber diameter compared with applied voltage and collection distance. The effects of different spinning process parameters on the productivity of nanofibers are investigated. High-quality nanofibers with small nanofiber diameter and error can be fabricated successfully. The average nanofiber diameter is 108 ± 26 nm. The average error is 24%. The productivity of nanofibers can reach 4.85 ± 0.36 g/h, which is about 24 times more than that of the single-needle method. This novel linear flume spinneret needleless electrospinning technology exhibits huge potential for mass production of nanofibers in the field of industrialization.


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