Field Assisted Sintering of Advanced Ceramic Materials

Nikhil MohipSeth MongbehAlejandro Vera Advisor: Professor Zhe Cheng

Presentation OutlineProblem Statement

◦Project Description◦Motivation and Goals

Literature Survey◦Sintering◦Sintering Driving Force◦Sintering Types◦Field Assisted Sintering

Presentation OutlineFlash Sintering Mechanism

◦Joule HeatingRelated Standards

◦International Organization of StandardizationChallengesGlobal Design ComponentsInitial Die DesignDie Design Alternatives

Presentation OutlineProposed System Design2015 Time LinePoster Board

Problem StatementProject Description:

◦Design and build a Flash sintering machine.

◦Successfully Flash sinter a sample or samples of ceramic material.

◦Record sample’s temperature in real time.

◦Test the sample’s mechanical properties.

Problem StatementMotivation and Goals:

◦Control or eliminate undesirable reactions to high temperatures.

◦Reduce harmful and unwanted waste.

◦Investigate the Flash sintering mechanism.

Literature SurveySintering:

◦Inter - particle pores in a granular material are eliminated by atomic diffusion.

Sintering Driving Force:◦ The curvature of the particle surface ◦ An externally applied pressure ◦ Chemical reaction

Literature SurveySintering Types:

◦Pressure Assisted Sintering.◦Hot Pressing.◦Microwave Sintering.◦Field Assisted Sintering

Literature SurveyField Assisted Sintering:

◦Use of a DC electric current in the sintering process cause retardation in growth grain.

◦Ceramics could be sintered in less than 5 seconds .

◦Relating common used materials are: Mg-O Alumina, SiC, and ZrB2.

Literature SurveyJoule Heating:

◦ Increment in the sample temperature from the scattering of electrical energy.

◦Assumes the sample transmits radiation like a dark body.

Flash Sintering MechanismJoule Heating:

◦Volumetric thermal expansion caused by increase in temperature.

Related StandardsInternational Organization for

Standardization:◦ISO has published more than 19500

International Standards covering almost every industry.

Related Standards

ChallengesAssemble a Field Assisted Sintering apparatus centered

around the FIU Nano – Fabrication Lab furnaces.

Densify material up to 90% then aim to increase densification.

Record temperature increase in real time.

Global Design Components• Conversion of currency

• Translation of the experimental design procedures

• Contacting of individuals who have performed flash

sintering experiments

Initial Die Design

• Conventional die used to press ceramic powder• On the outsides is the die assembly• In the middle is the press used to apply pressure

Die Design Alternatives

• Dog-bone shaped sample found to have even current distribution

• Rectangular die less complex to manufacture

Proposed System Design

• On far left – top view of flash sintering system• Middle – front view of die and sample being pressed• On right – close-up of sample while in furnace

2015 Time Line

FIELD-ASSISTED SINTERING OF ADVANCED CERAMIC MATERIALS

Problem Statement

• An economical and efficient way to investigate the flash sintered material’s mechanical properties, and to compare these properties to those of conventional sintering processes.

Motivation• Study the mechanism of flash

sintering.

• Understand how flash sintering influences the ceramic material and its properties.

• Further material research conducted by the Florida International University’s Mechanical and Materials Engineering Department.

Challenges

Objectives• Become pioneers in the subject of

flash sintering for the Florida International University’s Department of Mechanical & Materials Engineering.

• Successfully flash-sinter a sample or samples of ceramic material.

• Propose optimization of this process as part of the manufacturing of ceramic objects.

Global Learning• Converting currencies .

• Translate the experimental design.

• Warning labels in different languages.

• Contacting previous flash sintering designers from other countries.

Proposed Design

Time Line

 Advisor: Professor Zhe Cheng

•Assemble a flash sintering machine centered around the FIU Nano – Fabrication Lab furnaces.

•Densify material up to 90% then aim to increase densification.

Nikhil Mohip Seth Mongbeh Alejandro Vera