Dissertation > Excellent graduate degree dissertation topics show

Diffuse Interface Field Variable Models Simulation of Grain Growth in Welding Heat Affected Zones

Author: LiGang
Tutor: LiuXinTian
School: Zhengzhou University
Course: Materials Processing Engineering
Keywords: diffuse interface field variable models heat affected zones grain growth welding thermal cycle curve
CLC: TG401
Type: Master's thesis
Year: 2006
Downloads: 224
Quote: 0
Read: Download Dissertation

Abstract


Grain size is important performance indicators of metal materials. The crystal grain size directly affects material plasticity, resilience, strength, extensional, corrosive resistant, etc. Heat effect is inevitable in the Welding process, often causing welding heat affected zones (HAZ) to the crystal grain rough as a whole welding joints, which makes it the weakest link performance. Therefore, predictions of the HAZ ultimate crystal grain size distribution and crystal grain size distribution plays a key role for the quality control of welding joints. The paper took advantage of the diffuse interface model to simulation study of crystal grain grown up process in the welding HAZ of industrial pure aluminum(1060).The validity of the diffuse interface was preliminary proved through the simulation of small circle crystal grain contraction process in the infinity matrix. Then, with the variable model of diffuse interface field, dynamics process of normal crystal grain growing of industrial pure aluminum was simulated. The result of crystal grain grown up index was 0.49, which is very close to theoretical index.With the tungsten electrode argon-arc welding test, industrial pure aluminum: welding heat cycle curve was established. And contrasting the actual welding thermal cycle curve with the simulation of welding thermal cycle curve, using the origin software to do nonlinear fit, and the result got the simulation welding heat cycle curve which is close to the actual cycle curve. It was for welding heat affected zone crystal grain to lay a foundation. Through welding heat simulation tests, measuring the crystal grain size at the different temperature and in the different keeping temperature conditions. Using regression analysis to get the relation of crystal grain size and keeping temperature time, and establishing dynamics formula of crystal grain growing up in a welding HAZ. And comparing the result with welding test, certificating temperature gradient to "thermal nails Norte " action of crystal grain growing up, and the coefficient of thermal nails Norte is between 0.79-0.96. Amending dynamics formula of industrial pure aluminum crystal grain growing up in the welding heat

Related Dissertations

  1. Research on Zinc Oxide Varistors Doped with Rare Earth Oxides,TM54
  2. Grain Growth Kinetic of Co Nanocrystalline Prepared by High-Energy Ball Milling,TB383.1
  3. Study on Structure and Properties of WC-10Co Alloys by Microwave Sintering,TF125.3
  4. Preparation and Electric Properties of NBT-KBT Lead-Free Pizoelectric Textured Ceramics,TQ174
  5. The Kinetic Behaviour of Grain Growth in Weld Heat-Affected Zone,TG40
  6. Preparation process on the densification and microstructure of nano- alumina,TB383.1
  7. Characterization of Film-substrate Interface Structure and Its Energy Calculation,O484
  8. The Temperature Field Simulation of Fine Grain TC4 Titanium Alloy and Studying of Grain Growth,TG402
  9. Spray forming characteristics of high - temperature alloys and the study of the variation,TG132.32
  10. Effects of Sowing Date and Harvesting Date on Growth and Yield of Summer Corn (Zea Mays. L),S513
  11. The Preparation of Porous Alumina Ceramics and Monte Carlo Simulation of Crystals Organization Evolution,TQ174.12
  12. Research on Evolution of Microstructure in Low Carbon Steels for Fasteners,TG142.11
  13. Study on CO2 Laser Welding of Zinc Coated High Strength Steel,TG456.7
  14. Atomistic Simulations for Thermodynamic Properties of Nanostructured Metals and Alloys,TG111.3
  15. Physiological Effects of Post-Anthesis High Temperature and Water Stress on Wheat Quality Formation,S512.1
  16. Effects of Elevated CO2 on Leaf Growth, Sucrose Transport and Grain Filling in Rice （Oryza Sativa L.） and Their Mechanism,S511
  17. Study on the Simulation Models of Annealing Process and Related Computer Emulation Key Technologies by Monte Carlo Method,TG156.2
  18. Simulation of Grain Growth in the HAZ of Industrial Pure Aluminum,TG441
  19. Preparation and Mechanism of BaTiO3 and Tabular SrTiO3 by Molten Salt Synthesis,TB39
  20. China 's grain output and farmers' income collaborative system,F326.11
  21. Simulation of Microstructure Evolution During Welding Solidification of Nickel-based Alloy,TG401

CLC: > Industrial Technology > Metallurgy and Metal Craft > Welding, metal cutting and metal bonding > Welding general issues > Welding Metallurgy problems
© 2012 www.DissertationTopic.Net  Mobile