Accession Number:

AD0669250

Title:

RELATIONSHIP BETWEEN SEGREGATION SUBSTRUCTURES AND CASTING STRUCTURES.

Descriptive Note:

Technical rept.,

Corporate Author:

COMISION NACIONAL DE ENERGIA ATOMICA BUENOS AIRES (ARGENTINA) DEPARTAMENTO DE METALURGIA

Report Date:

1968-03-01

Pagination or Media Count:

78.0

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

Subject Categories:

  • Properties of Metals and Alloys
  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE