by Sergio L. Moren An Engineering Project Submitted to the Graduate

The Deformation Effects of Aluminide Over the Pack Coatings Diffusion Cycles on an Inconel 600 Coating Boat Lid

(Rectangular Plate)

bySergio L. Moren

An Engineering Project Submitted to the GraduateFaculty of Rensselaer Polytechnic Institute

in Partial Fulfillment of theRequirements for the degree of

MASTER OF MECHANICAL ENGINEERING

Problem: An Inconel 600 coating vessel lid deforms (potato chips) after a certain amount of coating cycles.

Purpose: The purpose of this Engineering project is to obtain an approximate life expectancy for the Inconel 600 vessels based on the deformation of the Lid.

Not actual tooling

Above-the-pack diffusion coating process:

Aluminide coatings rely on the formation of βNiAl on the surface of the component alloys. There are three processes by which aluminide vapor coating can be performed:

Pack processAbove-the-pack processChemical Vapor Deposition

This project addresses tooling issues related to the above-the-pack coating process:Process Temperature - 2000 ºF Activator – Halide (NaCl, CrCl2, NH4Cl, or

AlF3)Source Element – Aluminum CompoundProcess type – “Low Activity” and

“Outward Diffusing” Ni

Why does the Inconel 600 deform?

The stresses and strains involved in the thermal fatigue in bimetallic specimens is a contribution of the CTE (Coefficient of Thermal Expansion) mismatch between the coating and the alloy.

NiAl CTE @ 1600 ºF (871 ºC) ≈ 8.33 / ºF Inconel 600 CTE @ 1600 ºF ≈ 9.0 / ºF

Further analysis will be conducted to calculate the CTE at 2000 ºF

Deformation Mechanism of a Bimetallic:

111

11101 T

ER

y

222

22202 T

ER

y

dx

u1010

dx

u2020

R

H

dx

uu

dx

u

102012

R

H 102012

After integrating the strain equations twice over the area the deformation equation is obtained:

HyAEIEIE

MMEMETTyAE

Rtt

1112211

22211111221111

Project Status:

Format – customized the template provided

Research – obtained all reference required to do the background and methods

Methodology –

- need to conduct ANSYS analysis of the sample problems and apply it to the Inconel 600 plate- first coating run on Inconel 600 samples started on 3/10/2008 (no manufacturing window until that date)- send specimens to the lab to measure coating thickness

Should be able to complete all tasks by the required date. Looking to obtain at least 6 coating runs for the six samples.