Weldability of ductile nickel aluminides
A study was conducted to characterize hot ductility and heat-affected zone (HAZ) cracking behavior as a function of microstructure for a series of Ni/sub 3/Al-based alloys. Slip path length was influenced by grain size and antiphase domain (APD) structures. Grain size was varied by isothermal annealing, and APD structures were produced by oil quenching from temperatures above the ordering transition temperature. The ordering temperature was lowered by adding up to 8 at. pct chromium to a Ni/sub 3/Al+Hf+B alloy. Hot ductility and weldability correlated with grain size and antiphase domain (APD) size. Grain refinement and APD structures reduced slip path lengths and improved hot ductility. In general, hot ductility increased in high chromium alloys, and the highest ductility was observed in alloys with extensive APD structures. A model was developed to describe how a disordered skin at an antiphase domain boundary (APDB) influenced dislocation motion and reduced slip path length. HAZ cracking susceptibility was characterized by performing full penetration autogenous electron beam welds on 0.76 mm sheet. Welds with higher chromium content were less prone to HAZ cracking during welding, and slower welding speeds minimized cracking tendency in all alloys. 85 refs., 86 figs., 6 tabs.
- Research Organization:
- Oak Ridge National Lab., TN (USA); Colorado School of Mines, Golden, CO (USA). Center for Welding and Joining Research
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5710026
- Report Number(s):
- ORNL/Sub-85-27421/03; MT-CWR-089-033; ON: DE89017452
- Country of Publication:
- United States
- Language:
- English
Similar Records
Welding and weldability of nickel-iron aluminides
Weldability of Ni/sub 3/Al-type aluminide alloys
Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CHROMIUM
CRACKS
CRYSTAL STRUCTURE
DIAGRAMS
DUCTILITY
ELEMENTS
GRAIN SIZE
HEAT AFFECTED ZONE
HEAT TREATMENTS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
MICROSTRUCTURE
NICKEL ALLOYS
PHASE DIAGRAMS
SIZE
TENSILE PROPERTIES
TRANSITION ELEMENTS
WELDABILITY
ZONES