US 11,299,428 B2 · High strength ceramics with novel fracture mode

Abstract

The present invention provides a method for making a high strength, small grain size ceramic having a trans-granular fracture mode by rapid densification of a green body and subsequent cooling of the densified ceramic. The ceramic may include dislocations, defects, dopants, and/or secondary phases that are formed as a result of the process and resulting in stress fields capable of redirecting or arresting cracks within the material. This ceramic can maintain transparency from ultraviolet to mid-wave infrared.

Claims6

Dependent claims

A method for making a ceramic having transgranular fracture behavior, comprising:

forming a green body comprising a ceramic powder;
densifying the green body using microwaves to heat the green body at a rate of 100° C./min to 1450° C. and then holding at 1450° C. for 15 minutes, wherein a ceramic is formed, wherein there are dislocations within the ceramic, and wherein the microwave frequency is greater than 30 GHz;
and
cooling the ceramic to room temperature to trap the dislocations in the ceramic, resulting in a ceramic having a transgranular fracture mode.

1 more element

Dependencies are inferred from the claim text.

Facts

Application

15/498,709Filed 27 Apr 2017 · us provisional application

Priority

27 Apr 2016

Published

US 2017/0313626 A12 Nov 2017

Granted

12 Apr 2022

Term ends

Not estimatedThe source records don’t support an estimate.

Classification24 codes

C04B 35/505
Based on rare-earth compounds: based on yttrium oxide
C04B 35/443
Based on aluminates: magnesium aluminate spinel
C04B 35/4682
Based on barium titanates: based on BaTiO3 perovskite phase
C04B 35/50
Shaped ceramic products characterised by their composition ; Ceramics compositions ; Processing powders of inorganic compounds preparatory to…

High strength ceramics with novel fracture mode

Life of this patent

High strength ceramics with novel fracture mode

Life of this patent

Abstract

Claims6