Dissertation > Excellent graduate degree dissertation topics show

Study on DC Casting of Aluminum Alloy under the Dual-frequency Electromagnetic Fields

Author: LiJiXiang
Tutor: CuiJianZhong；ZhaoZhiHao
School: Northeastern University
Course: Materials Processing Engineering
Keywords: low frequency electromagnetic field intermediate frequency electromagnetic field dual-frequency electromagnetic fields Al alloys semi-continuous casting surface quality as-casting microstructure
CLC: TG292
Type: Master's thesis
Year: 2009
Downloads: 33
Quote: 0
Read: Download Dissertation

Abstract


This subject is a part work of "Research on solidification behaviors during semi-continuous casting of aluminum alloy under dual-frequency combined electromagnetic fields", which is supported by Young Teachers Fund Project of the Ministry of Education. The main purpose of this work is to develop a new casting process under dual-frequency electromagnetic fields, and then to obtain aluminum alloy ingots with high metallurgical quality.The content of this study includes the design of three kinds of dual-frequency electromagnetic combined fields DC casting sets by changing the location of two inductors and introducing electromagnetic shielding. The effects of the low- frequency electromagnetic field, intermediate-frequency electromagnetic field, and dual-frequency electromagnetic fields on the ingot’s quality were investigated under the three kinds of sets. The principles of the electromagnetic fields improving the as-casting microstructure and surface quality was analyzed.The main results are as followings:(1) When the low frequency inductor was placed under the intermediate frequency inductor, the electromagnetic fields formed by the two inductors can’t force on the melt near the graphite ring in the DC casting process simultaneously because of the long distance from the low-frequency inductor to the mould, so that the effect of low-frequency electromagnetic field on the as-cast structure was not obvious. The intermediate-frequency electromagnetic field can change the surface shape of melt in the DC casting process, so the surface quality of the ingots was improved and the segregation layer of the ingots reduced with the application of intermediate-frequency electromagnetic field.(2) When the low frequency inductor was placed in inner of the intermediate frequency inductor, the electromagnetic fields formed by the two inductors can force on the melt near the graphite ring in the DC casting process simultaneously. As only the low-frequency electromagnetic field was applied in the DC casting process, the as-casting microstructure of the whole ingot was fined obviously. As only the intermediate-frequency electromagnetic field was applied in the DC casting process, the as-casting microstructure in the edge of the ingot was fined obviously, but the microstructure in center was coarse. As the low-frequency electromagnetic field and intermediate-frequency electromagnetic field were applied simultaneously in the DC casting process, the refining effect of the low-frequency electromagnetic field on cast microstructure was weakened by the thermal effect, so the effect of dual-frequency electromagnetic fields on improving the as-casting microstructure was not better than that of low-frequency electromagnetic field.(3) When the low frequency inductor was placed in the inner of the intermediate frequency inductor, and an electromagnetic shielding was used. As only the low-frequency electromagnetic field applied in the DC casting process, the as-casting microstructure of the whole ingot was fined obviously. As the low-frequency electromagnetic field and intermediate-frequency electromagnetic field were applied simultaneously in the DC casting process, the as-casting microstructure was as fine as that of only applying low-frequency electromagnetic field. So the electromagnetic shielding can eliminate the negative effect of the intermediate-frequency electromagnetic field on the as-casting microstructure effectively.In summary by reasonable placement of the two inductors and suitable electromagnetic shielding in the DC casting process the dual-frequency electromagnetic fields can improve the as-casting microstructure and the ingot surface quality effectively.

Related Dissertations

  1. Study on Theory and Experiment of Wire Drawing with Composite Ultrasonic Vibration,TG663
  2. Research on Squeeze Casting Technology for High Strength and Toughness Aluminum Alloy Parts,TG249.2
  3. Study on Design of High Performance Al-Si-Cu-Mg Alloy,TG146.21
  4. Research on Role of Electrolyte in Electrolyte- Plasma Processing Technology,TM912
  5. Research on Microstructure and Property of Slow Shot Aluminium Alloy Die Casting,TG249.2
  6. Study on Squeeze Casting Process of 2024 Aluminum Alloy Hollow Axle Body of Transmission Shaft,TG249.2
  7. Superhard alloy 7A04 speed milling Serrated Chip,TG54
  8. 3003 aluminum alloy the ultrasonic continuous casting and rolling industrial experiments and Mechanism of,TG339
  9. Study of Microstructure, Mechanical Properties and Electroless Plating of a Fresh Magnesium Alloy Prepared by Investment Casting,TG249.5
  10. Producing Mg2Si（Si）/Al Gradient Composites by Centrifugal Casting and Study on Wear Ability,TB331
  11. Research on Soft-contact Electromagnetic Continuous Casting Technology of Ultra High Strength Aluminium Alloy Slabs,TF807
  12. Study of Electromagnetic Casting and Strengthening-Toughening of High Strength Aluminum Alloy,TG21
  13. The Research of Die-casting Process and Properties of High Si Al-based Alloys,TG249.2
  14. Preparation of Al2O3p/Al-Cu Matrix Semi-solid Billet,TG24
  15. Structures and Properties of Pistons of SiC Particle Reinforced Aluminum Composite Formed by Centrifugal Casting,TB331
  16. Research on Microstructure and Friction Performance of Mg2Si/Al Gradient Composite Materials by Centrifugal Casting,TB331
  17. Study on the Influencing Factors on Wet H2S Stress Corrosion Cracking Test of Oil Tube Shanghai Jiao Tong University,TE988.2
  18. The Research on the Microstructures and Mechanical Properties of ZA60 Alloys by Solid-Liquid Mixed Casting,TG136.1
  19. Experiment Research on High Speed Machining of Titanium Alloy with PCBN,TG506
  20. Surface Quality Analysis of Magnesium Alloy Sheet Based on Abrasive Belt Grinding and Grinding Technological Parameter Prediction,TG580.6
  21. Computer Simulation of Microstructure During the Ohno Continue Casting Processes,TG249.7

CLC: > Industrial Technology > Metallurgy and Metal Craft > Casting > Non-ferrous metal casting > Light metal casting
© 2012 www.DissertationTopic.Net  Mobile