Joining of advanced aluminides: Final report. [Ni/sub 3/ Al--8% Ev with and without Zr modifications]
The weldability of four Ni/sub 3/Al-8% Cr alloys (IC-221, and two low- Zr modifications) was investigated. Solidification segregation during base metal production decreases weldability by creating low-melting regions susceptible to hot cracking during welding. Extrusion, hot rolling, and annealing procedures were developed to homogenize the base metal microstructure, solving this problem. Weldability was evaluated with the gas tungsten arc welding process and heat-affected zone simulation (Gleeble testing) as a function of Zr content, preheat temperature, and weld travel speed. Weld cracking occurred in the fusion zone; no cracks originated in base material or HAZ. Cracking increased with Zr content at low Zr levels, increased with welding speed, and decreased with preheat. At higher Zr levels, hot cracking was severe, possibly due to a Zr-Ni eutectic. An interdendritic phase present at higher welding speeds, apparently /beta//prime/, is strongly enriched in Ar, and may be associated with weld cracking. Antiphase domains consisting of ordered /gamma//prime/ material surrounded by disordered /gamma/ form on rapid cooling and depend in size on welding or simulated welding cooling rates, and can be expected to affect weld metal properties. The high temperature welding thermal cycle properties of reduced Zr materials are comparable to those of the higher-Zr IC-218 and IC-221. 29 figs., 4 tabs.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls (USA)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 6911281
- Report Number(s):
- EGG-MS-8000; ON: DE88015111
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
ALLOYS
ALUMINIUM ALLOYS
ARC WELDING
CHROMIUM ALLOYS
CRACKS
DOCUMENT TYPES
FABRICATION
FRACTURE PROPERTIES
GAS TUNGSTEN-ARC WELDING
JOINING
JOINTS
MECHANICAL PROPERTIES
NICKEL ALLOYS
PROGRESS REPORT
TENSILE PROPERTIES
WELDABILITY
WELDED JOINTS
WELDING
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS