Please consider attending this seminar:

 

MATERIALS ENGINEERING

SEMINAR

 

“The Influence of Print Layer Orientation on the Mechanical Properties of SiC and C_f/SiC CMCs Formed via Direct Ink Writing”

By

Kyle Cox

                                                                                                                                                                                  Purdue MSE M.S. Final Exam

 

Advisors: Professor Rodney Trice and Professor Jeff Youngblood

 

ABSTRACT

 

Silicon carbide is a useful monolithic and matrix ceramic due to its excellent mechanical properties and corrosion/oxidation resistance at high temperature. This makes it an attractive material for use in advanced applications, such as aircraft engines and high-speed flight. In this study, additively manufactured monolithic SiC and C_f/SiC CMCs, processed via direct ink writing (DIW) of a 53 vol% colloidal suspension, achieved >96% theoretical density through pressureless sintering. When present, fibers are aligned in the direction of the print path. Five different print paths were studied, including a 0^o path, 90^o path, 0/90^o path, 0/15/30/45/60/75/90^o path, and 0/30/60/90/60/30/0^o path. Four-point bend testing was performed to determine flexural strength and Weibull analysis was performed. Strengths were highest for the 0^o print path. The characteristic strength, σ_o, of this print path was 375 MPa with a Weibull modulus of 7.4 for monolithic SiC and a σ_o of 361 MPa with a Weibull modulus of 10.7 for C_f/SiC. Weibull modulus was greater for C_f/SiC samples compared to identically printed monolithic SiC samples. SEM and optical microscopy were used to analyze printed parts which showed a high degree of fiber alignment in the direction of the print. Fiber pullout was observed on the fracture surface, as well as intragranular fracture.

 

 

 

Date: Tuesday, November 30, 2021

Time: 11:30 A.M.

Place: by Webex https://purdue.webex.com/meet/rtrice