Data Driven Approach toward Ultra-High Temperature Tough Ceramics by way of Heterogeneity at Multipl
Abstract
Approved for Public Release[Research Problem:] Ceramics are material of choice for high temperature applications, e.g., hypersonics,flights. However, their extremely low toughness poses major limitations.[Goal:] Our goal is to establish a systematic knowledge of t,oughening mechanisms in pyrolyzed-sintered heterogeneous ceramics composed of three phases, polymer-derived ceramics (PDC), nanofill,ers embedded in PDC matrix and particle ceramics (non-PDC), with a focus on roles of interfacial interactions. By virtue of tailorab,le heterogeneity and interfaces, we hypothesize that this material provides a platform to impart major toughening at temperatures as, high as 2000?C via mechanisms at several length scales: (i) sub-micron scale, e.g., nanofiller pull out, (ii) microns, PDC and non-,PDC interface, and (iii) 10-200s of microns, geometric heterogeneity by means of Ceramic On Demand Extrusion (CODE). This is motivat,ous heterogeneity. Novelties: Data driven interface design, potential synergistic toughening by hybrid nanomaterials in ceramics, an,ng will be used to accelerate experiments in three Aims. As testbed, three phases of our ceramic are: nanofillers (carbon nanofiller,), PDC (SiC from polycarbosilane precursor), and particle ceramic (ZrB2 and ZrC). This is selected based on PIs experiences to facil,itate experiments. In Aim 1, we will utilize multiscale atomistic models, enhanced with deep learning neural network and experimenta,l validation/verification, to understand microstructure evolution in pyrolysis/sintering. The focus will be on interfacial interacti,ons that control microstructure at the sub-micron and micron scale. The effect of thermal profile on bonding (van der Waals or coval,ent) will be studied. Master sintering curves will be achieved. In Aim 2, we will establish microstructure-mechanics relations, at s,ub-micron and microns. First, effects of nanofiller on PDC mechanics will be studied (no non-PDC), with pyrolysis process guided by,Aim 1 to control PDC-nanofiller interface. Then, we will identify the mechanics of three-phase ceramic as a function of sintering co,nditions, with process parameters guided by Aim 1. The strength and toughness will be studied via flexure test at room temperature t,o ~2200?C. Material characterization will identify failure mechanisms in relation to interfacial interactions from Aim 1. Next, syne,rgistic toughness augmentation by hybrid nanomaterials, i.e., 1D and 2D nanomaterials, will be studied. In Aim 3, we will develop al,gorithms to design tough heterogeneous ceramics. This will benefit from properties measured in Aim 2 and computationally efficient m,achine learning reduced order (MLRO) algorithms informed by Physics informed ML. We will proceed with experimental evaluation of mec,hanics of heterogeneous ceramics fabricated made via the highly versatile CODE.[Anticipated outcome:] We will establish big data and, validated models to capture evolution of microstructure during pyrolysis/sintering with nanofillers. We will identify the microstru,cture-mechanics relations in these ceramics, including synergistic effects with mixed dimensional nanofillers. We will identify ,tune toughening mechanisms in heterogeneous ceramics at multiple length scales, from nanometers to 10s of microns by means of artifi,cial intelligence design algorithms.[Impact on DOD:] This effort will greatly enhance the ability of the DOD to design tough ceramic,s at multiple length scales. Given the large number of variables involved, this work will set the foundation for modeling-driven des,ign for toughness-augmented heterogeneous ceramics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 04, 2022
- Source ID
- N000142312009
Entities
People
- Mohammad Naraghi
Organizations
- Office of Naval Research
- Texas Engineering Experiment Station
- United States Navy