Thermally induced grinding damage in cast equiaxed nickel-based superalloys

Thesis/Dissertation · Wed Jan 01 04:00:00 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
• Country of Publication: United States
• Language: English

Related Subjects

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