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Correlation of processing and sintering variables with the strength and radiography of silicon nitride
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Baaklini, G. Y. Sanders, W. A. |
| Copyright Year | 1986 |
| Description | A sintered Si3N4-SiO2-Y2O3 composition, NASA 6Y, was developed that reached four-point flexural average strength/standard deviation values of 857/36, 544/33, and 462/59 MPa at room temperature, 1200 and 1370 C respectively. These strengths represented improvements of 56, 38, and 21 percent over baseline properties at the three test temperatures. At room temperature the standard deviation was reduced by over a factor of three. These accomplishments were realized by the iterative utilization of conventional x-radiography to characterize structural (density) uniformity as affected by systematic changes in powder processing and sintering parameters. Accompanying the improvement in mechanical properties was a change in the type of flaw causing failure from a pore to a large columnar beta- Si3N4 grain typically 40 to 80 microns long, 10 to 30 microns wide, and with an aspect ratio of 5:1. |
| File Size | 3085271 |
| Page Count | 38 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19860022257 |
| Archival Resource Key | ark:/13960/t0ms8m89q |
| Language | English |
| Publisher Date | 1986-01-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Grain Size Ceramics Density Distribution Nonuniformity Flexing X Ray Density Measurement Radiography Voids Bend Tests Sintering Silicon Nitrides Fracture Strength Fracturing Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
