Effect of Heat Treatment on Microstructure and Mechanical Properties for a Ni3Al Base Single Crystal Alloy DDIC6

Zhi Gang Kong; Lei Ji; Shu Suo Li; Ya Fang Han; Hui Bin Xu

doi:10.4028/www.scientific.net/MSF.546-549.1443

Paper Titles

A Novel Canning Technology for Forging of Gamma-TiAl Alloys
p.1421

Mechanical Property and Elastic Modulus of Metastable Ti-Nb Based Alloys with Si Addition
p.1427

Influence of Rapid Solidification on the Microstructure and Mechanical Properties of NiAl-Based Near Eutectic Alloys
p.1431

Study on Fracture Behavior of γ-TiAl Based Alloys
p.1437

Effect of Heat Treatment on Microstructure and Mechanical Properties for a Ni₃Al Base Single Crystal Alloy DDIC6
p.1443

Microstructure Evolution of Ti-Al Peritectic System during the Initiated Stage of Directional Solidification
p.1447

Theoretical Prediction of Ternary Site Occupancies in ZrCr₂ and NbCr₂ Laves Phases
p.1451

First-Principles Study on Initial Oxidation of NiAl(110)
p.1455

Study of Hot Deformation Characteristics of an As-Cast Ti-22Al-25Nb Alloy
p.1461

HomeMaterials Science ForumMaterials Science Forum Vols. 546-549Effect of Heat Treatment on Microstructure and...

Effect of Heat Treatment on Microstructure and Mechanical Properties for a Ni₃Al Base Single Crystal Alloy DDIC6

Abstract:

The effect of heat treatment on microstructures and stress rupture property of a Ni3Al base single crystal alloy DDIC6 was studied in the present investigate. The single crystal specimens were produced by screw selection crystal method. The heat treatment for the alloy was 1300°C/10h+1120°C/4h+870°C/32h and 1300°C/10h+870°C/32h.The microstructures were examined by SEM, TEM and X-ray EDS techniques. The stress rupture tests were carried out in air by constant load creep machines under 1100°C/130MPa with the specimens size of φ5×25 mm. The experimental results showed that the as-cast large size γ′ phases entirely dissolved after 1300°C/10h, and secondary fine γ′ phases precipitated by following aging at 1120°C and 870°C for certain periods of time. The stress rupture life under 1100°C/130MPa increased from 20~30hrs for as-cast condition to 60~100hrs for heat treatment condition. The improvement of the creep resistance of the alloy may attribute to the decrement of the elements segregation at dendrite and interdendritic areas, and the proper size and distribution of γ′ phases.