An Analytical and Experimental Study of the Grinding Process of Thermal Barrier Coatings With Highly Porous Wheels of Cubic Boron Nitride

EasyChair Preprint 1778

Abstract

To protect heat-resistant alloys from high-temperature oxidation, thermal barrier coatings are widely used. Practical application, in accordance with the requirements arising during operation, found a coating of ZrO₂. Zirconia based ceramics are highly durable and crack resistant. In the grinding process, high contact temperatures arise, the values of which are comparable to operating temperatures or slightly higher than these temperatures.

The task in the design of the grinding process is primarily to control the thermal treatment mode in order to maintain it within such limits when the residual stresses have values that do not pose a danger to the durability of the sprayed layer.

In addition, if the contact temperature of grinding reaches 1200ºС, then the sintering of the sprayed layer begins, which leads to the loss of thermal barrier properties.

When grinding with highly porous CBN wheels with a structure 26 and 40, the unit cutting forces are 15–20% higher, and the total cutting forces are 7–10% lower. When grinding with highly porous wheels, contact temperatures are 10-15% lower.

The residual stresses arising under the action of contact temperatures on the surface during grinding of pure zirconium oxide and stabilized with yttrium oxide reach values of the order of 60 MPa, however, these values are much lower than the tensile strength of the thermal barrier layer and do not lead to cracks.

When grinding with highly porous wheels, an increase in roughness by 1 category can be expected.

When grinding with highly porous CBN wheels grinding modes can be increased by 20-25%.

Keyphrases: Residual stresses, contact temperature, highly porous wheels, temporary stresses, total force, unit force, unit temperature

@booklet{EasyChair:1778,
  author    = {Vladimir Lebedev and Olga Frolenkova and Tatyana Chumachenko and Alla Bespalova and Oksana Faizulina},
  title     = {An Analytical and Experimental Study of the Grinding Process of Thermal Barrier Coatings With Highly Porous Wheels of Cubic Boron Nitride},
  howpublished = {EasyChair Preprint 1778},
  year      = {EasyChair, 2019}}