Thermally induced grinding damage in cast equiaxed nickel-based superalloys

Thesis/Dissertation · Wed Jan 01 00:00:00 EST 1986

OSTI ID:6953184

Kovach, J A

The overall objective of this program was to increase the understanding and productivity of conventional grinding operations utilized in the finishing of cast equiaxed nickel-based superalloy components. To achieve this overall goal a four phase approach was employed. Initially, a grinding energy partition relationship for conventional grinding of superalloys was developed. Secondly, the mechanisms and conditions that influence superalloy microcracking during abusive grinding were determined. Third, building on the above relationships, a means of readily predicting the onset of grinding damage in cast Rene-77 and B-1900 superalloys was established. Finally, the results were implemented in production surface grinding operations to increase superalloy grinding quality and productivity. Finite element analyses were utilized to determine the superalloy grinding zone temperatures and residual stresses. The results indicated that Rene-77 microcracks are not formed by the residual stresses alone. The effects of constitutional liquation or weakening of the grain boundaries due to rapid heating to such temperatures were shown to be significant. It was then demonstrated that workplace damage would occur when the combined conducted and convected heat flux exceeded a critical limit.

• Research Organization: Case Western Reserve Univ., Cleveland, OH (USA)
• OSTI ID: 6953184
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HEAT RESISTING ALLOYS
CASTING
GRINDING
NICKEL BASE ALLOYS
CRACKS
FINITE ELEMENT METHOD
HEAT FLUX
STRESS ANALYSIS
ALLOYS
COMMINUTION
FABRICATION
HEAT RESISTANT MATERIALS
MACHINING
MATERIALS
NICKEL ALLOYS
NUMERICAL SOLUTION
360101* - Metals & Alloys- Preparation & Fabrication