14. Uniaxial Compression Studies¶
14.1. Asymmetric Uniaxial Compression Testing Using ISO-T Anvils¶
Uniaxial compression testing is widely used for uniaxial compression expansion measurement of metals and alloys. To keep the deformation uniform during compression, temperature within the volume of the specimen must be uniform. Thermal uniformity can be achieved by furnace heating or induction heating. These methods require slow heating rates, and the material is allowed to soak for a long period of time, ensuring that an equilibrium temperature is reached.
Fig. 14.1 Uniaxial Compression Test.
he unique DSI direct resistance heating system can also provide uniform heating, but can do it much faster. In resistance heating, an isothermal plane across the diameter of a cylindrical specimen is always maintained during heating or cooling. The ISO-T anvil system developed at Dynamic Systems Inc. also eliminates the axial temperature gradient. This provides a uniform temperature throughout the entire volume of the specimen. Thus, the best features of resistance heating including, faster heating and cooling rates, easy specimen access, short soaking times, and direct fast quenching, are combined with the uniformity of temperature distribution found in furnace heating. This provide an excellent method for uniaxial compression testing at elevated temperatures.
Conducting Tests Using Gleeble’s Uniaxial Compression Testing Assemblies
To prevent barreling of the specimen, the application of suitable Diffusion Barriers at the interface between the anvils and the specimen is recommended. The diffusion barrier prevents diffusion bonding. This creates near frictionless contact between the specimen and the anvils. Allowing the specimen free movement against the anvils prevents any barreling.
Hot Deformation Software (HDS) can be used to perform a uniaxial compression test in conjunction with a Hydrawedge II.
14.2. Uniaxial Compression Anvil Assemblies¶
Uniaxial compression tests involve the compression of a specimen held between two anvil faces. Each anvil base kit below includes all components needed to perform simple uniaxial compression tests.
14.2.1. ISO-T Anvil Base Kits¶
General-Purpose MCU - Pocket Jaw Mounted
Fig. 14.2 Pocket Jaw Mounted - ISO-T Flow Stress Anvil Assembly - DSI# 9555-100.
| Part Number | Description | Sold As |
|---|---|---|
| 9555-100 | ISO-T Uniaxial Compression Anvil Assembly - General-Purpose MCU Pocket Jaws | Kit |
| 9555-110 | ISO-T Uniaxial Compression Anvil Assembly - Gleeble 3180 | Kit |
| 9555-200 | ISO-T Uniaxial Compression - Pocket Jaw Wedge Mount - General-Purpose MCU Pocket Jaws | Ea. |
| 9555-400 | ISO-T Uniaxial Compression - Anvil Mounting Block - General-Purpose MCU Pocket Jaws | Ea. |
| Used With All Uniaxial Compression Anvil Assemblies | ||
| 9555-504 | ISO-T Copper Backup Plate - 28.575 mm (1.125 in) dia | Ea. |
| 9555-503 | Graphite Disk - 10 mil thick | Ea. |
| HH390 | Set Screw - Secures Anvil Assembly into Mounting Block | Ea. |
| HH245 | Bolt - Secures Anvil Mounting Block | Ea. |
Hydrawedge II or Compression Tester Adapter Mounted
Fig. 14.3 Hydrawedge II Mounted - ISO-T Flow Stress Anvil Assembly - DSI# 9555-101.
| Part Number | Description | Sold As |
|---|---|---|
| 9555-101 | ISO-T Uniaxial Compression Anvil Assembly - Hydrawedge II and Compression Testing Kit | Kit |
| 9555-303 | Uniaxial Compression Anvil Mount - Hydrawedge II and Compression Test Adapter Set | Ea. |
| GN2882K | Copper Backup Plate - Hydrawedge II and Compression Test Adapter Set | Ea. |
| 9555-301 | Uniaxial Compression Mounting Plate | Ea. |
| 9555-505 | ISO-T Anvil Mounting Block - Hydrawedge II | Ea. |
563 Pocket Jaw
Fig. 14.4 ISO-T Anvil Assembly - 563 - DSI# 9575-100.
| Part Number | Description | Sold As |
|---|---|---|
| 9575-100 | ISO-T Uniaxial Compression Anvil Assembly - 500 Series | Kit |
| 9575-500 | Compression Mounting Base | Ea. |
| 9575-501 | ISO-T Anvil Mounting Block | Ea. |
14.2.2. ISO-T Anvil Assemblies¶
ISO-T anvil assemblies require anvil caps, anvil bases, and interstitial conducting media typically graphite disks.
Standard ISO-T Anvil Assembly
Fig. 14.5 ISO-T Uniaxial Compression Anvil Assembly - DSI# 9555-102.
| Part Number | Description | Sold As |
|---|---|---|
| 9555-102 | ISO-T Tungsten Carbide Anvil Assembly | Ea. |
| 9555-501 | ISO-T Inner Containment Sleeve | Ea. |
| 9555-502 | ISO-T Outer Containment Sleeve | Ea. |
| 9555-506 | ISO-T Anvil Spring Clip | Ea. |
ISO-T Anvil Assembly - 6 mm Specimens
Fig. 14.6 ISO-T Uniaxial Compression Anvil Assembly - 6 mm - DSI# 9555-107.
| Part Number | Description | Sold As |
|---|---|---|
| 9555-107 | ISO-T Anvil Assembly - 6 mm dia specimens | Ea. |
14.3. Uniaxial Compression Anvils¶
DSI’s ISO-T anvils utilize interior layers of thermal and electrical resistance material to allow the user to adjust the anvil assembly temperature. Matching the anvil temperature to the specimen temperature will reduced the thermal gradient in the specimen.
For large samples, tests with less stringent thermal gradient requirements, or where the additional compliance of the resistance layers may be problematic, the multi-piece anvil stack can be replaced with a solid one piece, Non-ISO-T anvil.
Recommended Maximum Operating Temperatures for Compression Anvils Tungsten Carbide 1,200°C (2,192°F ) Pure Tungsten 1,400°C (2,552°F ) Tungsten Composite 1,700°C (3,092°F ) Quartz
Silicon Nitride
14.3.1. ISO-T Anvils¶
Fig. 14.7 ISO-T Tungsten Carbide Anvil Cap - Uniaxial Compression - DSI# 9219-062.
| Part Number | Description | Sold As |
|---|---|---|
| Anvils For Use With Standard 10 mm dia x 15 mm Uniaxial Compression Specimens | ||
| 9219-062 | ISO-T Tungsten Carbide Anvil Cap - Uniaxial Compression - 19.1 mm dia x 6.35 mm (0.75 in dia x 0.25 in) | Pack of 5 |
| 9555-500 | ISO-T Tungsten Carbide Anvil Base - Uniaxial Compression - 19.1 mm dia x 19.1 mm (0.75 in dia x 0.75 in) | Pack of 2 |
| Anvils For High-Temperature Studies | ||
| 9219-066 | ISO-T Uniaxial Compression Anvil Cap - High-Temperature - Pure Tungsten - 19.1 mm dia x 6.35 mm (0.75 in dia x 0.25 in) | Ea. |
| 9555-515 | ISO-T Uniaxial Compression Anvil Base - High-Temperature - Pure Tungsten - 19.1 mm dia x 19.1 mm (0.75 in dia x 0.75 in) | Ea. |
| 9220-069 | ISO-T Uniaxial Compression Anvil Cap - High-Temperature - Tungsten Composite - 20 mm dia x 6.5 mm (0.787 in dia x 0.255 in) | Ea. |
| Anvils For Use With 6 mm dia x 9 mm Uniaxial Compression Specimens | ||
| 9212-042 | Uniaxial Compression Anvil - 12 mm dia x 4 mm (0.472 in dia x 0.157 in) | Pack of 10 |
| 9555-510 | ISO-T Anvil Adapter Ring - 12 mm dia x 4 mm (0.472 in dia x 0.157 in) | Ea. |
| 9555-513 | ISO-T Uniaxial Compression Anvil Base - 12 mm dia x 4 mm (0.472 in dia x 0.157 in) | Ea. |
14.3.2. Non-ISO-T Anvils¶
Non-ISO-T anvils are are made as a single unit and do not require an anvil base or interstitial conducting medium.
Fig. 14.8 Non-ISO-T Tungsten Carbide Anvil - DSI# 9219-252.
| Part Number | Description | Sold As |
|---|---|---|
| 9219-252 | Tungsten Carbide Uniaxial Compression Anvil - 19.1 mm dia x 25.4 mm (0.75 in dia x 1.0 in) | Pack of 2 |
| 9219-253 | Stainless Steel Uniaxial Compression Anvil - 19.1 mm dia x 25.4 mm (0.75 in dia x 1.0 in) | Pack of 2 |
14.4. Specimen Loading Tools and Clips¶
Fig. 14.9 Specimen Loading Tool
For more information on Specimen Loading Tools and Clips can be found here.
14.5. Uniaxial Compression Testing Consumables Kits¶
Uniaxial Compression Consumables Kits contain many of the most commonly used consumables for the various compression testing methods.
14.5.1. Hot Compression Starter Kit - DSI# 9570-000¶
Kit 9570-000 contains the following parts:
| Part Number | Description |
|---|---|
| RMX005SB | 5 mil thick Graphite Foil |
| RMX004S | 4 mil thick Tantalum Sheet |
| RMX010SA | 10 mil thick Graphite Foil |
| HW008 | Super Bonder Glue |
| HW008A | Omega Bond Thermocouple Cement |
| HW014 | Anti-seize Compound - Nickel Paste |
| HW510 | Superlube |
14.5.2. Uniaxial Compression Consumables - DSI# Kit 9570-001¶
Kit 9570-001 contains the following parts:
| Part Number | Description |
|---|---|
| 9219-062 | ISO-T Tungsten Carbide Anvil Cap - Uniaxial Compression - 19 mm dia x 6.35 mm (0.75 in dia x 0.25 in) |
| 9555-102 | ISO-T Tungsten Carbide Anvil Assembly |
| 9555-504 | ISO-T Copper Backup Plate - 1.125 in dia |
| 9555-500 | ISO-T Tungsten Carbide Anvil Base - Uniaxial Compression - 19 mm dia x 19 mm (0.75 in dia x 0.75 in) |
| 9555-501 | ISO-T Anvil Inner Containment Sleeve |
| 9555-502 | ISO-T Anvil Outer Containment Sleeve |
| 9555-506 | ISO-T Spring Clip |
| 9555-503 | Graphite Disk - 10 mil |
| TU405 | Nextel Sleeving |
For additional consumable items see Gleeble Consumables.