REVIEW OF LITERATURE RELATED TO MICROSTRUCTURE DEVELOPMENT DURING LASER SURFACE ENGINEERING OF NICKEL ALUMINUM BRONZE

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Authors
  1. Hyatt, C.V.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
In the report, literature related to the low heat input welding of nickel aluminum bronze is examined. This includes data on phases present, composition effects, phase diagrams, transformation kinetics, and the nature of martensites. Relevant data on microstructure development in castings, wrought materials, conventional welds and low heat input welds is considered. So is related work on the examination of melt spun ribbons and Gleeble studies. Available data show that a martensite with a 9-R structure is common in low heat input nickel aluminum bronze welds over a range of compositions. Other structures are expected at other compositions. Data also show that for at least one alloy composition, formation of Widmanstatten alpha can be suppressed with a high enough cooling rate (finite difference t 800-500 of 1.6 seconds or faster). As well, data show that tempering of martensites in weld heat affected zones probably does not occur at temperatures of less than roughly 400C. The review shows that experiments to obtain data on ordering, metastable reactions, precipitation and tempering are needed. Also needed are experiments to understand the effect of composition and heat input on microstructure.
Keywords
Laser cladding;Phase transformation;Surface melting;Low Heat Input Welding
Report Number
DREA-TM-96-227 — Technical Memorandum
Date of publication
01 Mar 1997
Number of Pages
35
DSTKIM No
97-03180
CANDIS No
503239
Format(s):
Hardcopy;Document Image stored on Optical Disk

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