Dissertation > Excellent graduate degree dissertation topics show

Investigation of Techniques and Interface Structure and Mechanical Properties of the Explosive-welded QBe2/Q235 Composite Pate

Author: HouShuZeng
Tutor: ZhangGuoShang
School: Henan University of Science and Technology
Course: Materials Processing Engineering
Keywords: Metal composite materials Explosive welding Interface morphology Aging treatment Mechanical properties
CLC: TG456.6
Type: Master's thesis
Year: 2010
Downloads: 77
Quote: 0
Read: Download Dissertation

Abstract


In the mold manufacturing industry, the sliders and the guide plates are used widely standard parts, whose materials are high strength copper alloys, in particular, beryllium bronze (QBe2) was widely used. Beryllium-copper has high strength, high hardness, fatigue resistance, corrosion resistance, wear resistance and other excellent comprehensive performance, but the material is expensive, its plastic ductile property is poor, and its non-magnetic nature can cause problem to fix the grinding machining parts. In the conditions to meet the application requirements, if a layer of beryllium bronze is composed on low-cost mild steel (Q235) surface, the usage of expensive beryllium bronze is significantly reduced and the cost of mold standard parts is greatly reduced, at the same time the inconvenience in the processing of beryllium bronze due to non-magnetic characteristics is solved. Explosive welding is a very useful new technology and new technique for metallic composites production, by using explosives as energy resource. Explosive welding with unique advantage is applied widely to national defense and civil industry, and has great developing potency. In this paper, the explosive welding process and heat treatment processes of QBe2/Q235 composite plate were studied, the interface microstructure was analyzed by modern examination techniques, such as OM, SEM and EDS, and the mechanical properties of composite plate were tested by universal testing machines, wear testing machines and other equipments.The experimental results were shown that:1 The explosive welding performance of QBe2 after solution heat treatment was improved greatly. Satisfactory QBe2/Q235 composite plates were obtained with the three given loading doses. But the detonation point and the four corners of composite plate were not welded together for the boundary effect, and the boundary effect was eliminated by increasing the amount of explosives in detonation zone and by adding cushioned plate on the four corners.2 Interface shape of composite plate changed in turns from flat - wavelet - large wave - a stable large wave beginning with the detonation point; the grains at interface were broken, the grains of Q235 side were elongated into streamline shape, while the QBe2 side appeared adiabatic shear band; vortex with cast structure emerged before and after the waveforms, there were a few microns thick melt layers on wave ridges and a little Cu and Fe spread on the interface.3 The shear strength and the bond strength of QBe2/Q235 composite plate far exceeds the national standard of acceptance and the composite plate has a excellent cold bending property, in addition hardening phenomenon was occurred in the interface zone.4 Better aging process of QBe2/Q235 composite plate is: composite plate is aging for 3h at 15±5℃, the maximum hardness of QBe2 side can reach 36 HRC.5 Adiabatic shear lines disappeared of QBe2 side after aging treatment, and hardening phase emerged at grain boundary and in the grain that increased the wear resistance of QBe2 side whose wear volume was generally one-third of copper alloy slider. Moreover, diffusion was promoted on the one hand by aging treatment which improved the interface bonding strength, on the other hand the brittle of QBe2 increased greatly which cased adverse effects on mechanical properties.6 After aging treatment, shear strength of composite plate changed little, while the bond strength and cold performance was reduced.

Related Dissertations

  1. Reactive Hot-Pressing and Mechanical Properties of （ZrB2-ZrO2）/BN Composites,TB332
  2. Microstructure and Mechanical Properties of Mg-Zn-Y-Zr Alloys,TG146.22
  3. The Research on Extrusion Parameters Through the Plate Billet of Magnesium Alloy,TG379
  4. Effect of Adding ZrO 2 Nanopowder on Microstructure and Mechanical Properties of Carbon Steel,TB383.1
  5. Preparation of Surface-functionalized Graphene and Its Influence on the Mechanical Properties of Nanocomposite Materials,TB332
  6. Rolled Mg-Zn-Ce-Zr (Mn) alloy microstructure and mechanical properties of,TG339
  7. Heat Treatment of Cast Al-Cu-Ti-(La) alloy microstructure and mechanical properties of,TG166.3
  8. Longitudinal magnesium alloy AZ91 under AC magnetic field properties of welded joints,TG407
  9. Hot extruded Mg-Zn-Zr-Gd alloy microstructure and mechanical properties,TG379
  10. Si-containing magnesium alloy microstructure and mechanical properties,TG146.22
  11. Direct smelting crude magnesium AM50 magnesium alloy inclusions in the analysis,TF822
  12. Direct smelting crude magnesium AM60 magnesium alloy inclusions analysis,TF822
  13. Fabric softness subjective evaluation,TS101.923
  14. Rolled magnesium alloy ratcheting behavior and microstructure simulation,TG339
  15. Strain hardening austenitic stainless steel 022Cr17Ni12Mo2 low cycle fatigue properties of,TG115.57
  16. 2205 duplex stainless steel plate TMCP technology research,TG335.5
  17. High - speed railway bridges mitigation and isolation,U442.55
  18. Study on Mechanical Performance of Curved Box-girder with Corrugated Steel Webs,U448.213
  19. Study on Totally Bioresorbable Composites as Cardiovascular Stent Material,R318.08
  20. Study on Organic Additives Applied to Electrodeposited Copper Foil,TF811
  21. Cutting silicon brass performance study,TG146.11

CLC: > Industrial Technology > Metallurgy and Metal Craft > Welding, metal cutting and metal bonding > Welding process > Special welding > Explosive Welding
© 2012 www.DissertationTopic.Net  Mobile