FEASIBILITY DETERMINATION AND DEVELOPMENT OF AN EXPERIMENTAL HOT-MICROHARDNESS DEVICE SATISFACTORY FOR USE WITH CERAMIC MATERIALS TO TEMPERATURES APPROACHING 1800 TO 2000C.
Abstract
An elevated-temperature microhardness tester is described. This system is designed for operation at temperatures up to 2000 C in vacuum or inert atmosphere. The loading system is capable of applying calibrated loads of 50 to 1500 grams to the indenter. A system for classifying elevated-temperature indentations with respect to degration of quality by various mechanisms is described. Indenters that were evaluated are as follows: TiB2(Knoop), B4C (Vickers), B4C (Knoop), TaC (Knoop), W2C (Vickers), (Ta(0.8)Hf0.2)C(1+x) (Vickers), ZrO2 (Vickers), and (Ta0.9U0.1)B4 (Vickers). The most successful were B4C (Knoop) and TaC (Knoop) indenters. The former was most successful for indenting the borides and carbides and the latter for the oxides. The materials that were evaluated by hot-hardness determinations are TiB2, W2B5, ZrB2, HfB2, (Th0.9U0.1)B4, ZrO2, A12O3, ThO2, B4C, TiC, NbC, (W(0.65)Cr(0.14)Ta(0.07))2C, TaC(1-x')HfC(1+x') and (Ta(0.8)Hf(0.2))C(1+x). Plots of log hardness versus temperature and talbes of elevated-temperature hardness are inculded for most of these materials. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1966
- Accession Number
- AD0486817
Entities
People
- Del H. Fisher
- Donald P. Moak
- Robert D. Koester
Organizations
- Battelle Memorial Institute