RELATIONSHIP BETWEEN SEGREGATION SUBSTRUCTURES AND CASTING STRUCTURES.
Abstract
Contents: (1) Cellular solidification in HCP alloys of Zn-Cd grown unidirectionally. Node mechanism in substructure evolution and morphological features of dendritic stages emphasized. (2) Predentritic solidification, especial attention to columnar and equiaxed grains in Al-Cu alloys and Sn-Zn alloys. Also tridimensional model analysis used. (3) Studies of surface and subsurface structure of Al-Cu alloys, effects of mold, mold surface treatment (lamp black, graphite, copper). High heat extraction condition - copious nucleation is responsible for chill zone. Low heat extraction - coarse grain structure with dendritic morphology, size relates to convection. (4) Scale-up-of-ingot-size effects and magnetic field effects - in large sizes (500 - 5000 cc) poured in magnetic field coarse equiaxed region persists at center. Probable mechanism Winegard Chalmers. (5) Segregation substructures: origin and nature of chill zone; stability of crystal growing freely in bulk liquid; picture and degree of segregation in columnar region as function of alloy crystallography; grain boundary migration during cooling after solidification completed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0669250
Entities
People
- F. J. Kiss
- H. Biloni
- M. A. Audero
- R. Dibella
- R. Morando