Zeiss Xradia Versa 620 - Deben Microtest

Tensile Sample Preparation

• Sample dimension: It is suggest have maximum sample height ~ 31 mm, the physical distance (limit) between jaws are 30 to 40 mm. Please use the (best practice) schemes below to prepare the samples. Please note the top and bottom widest parts are for the purpose of holding the sample, and actual testing area are about 10-20 mm at center, and you should expect changes happening at the middle ( 1-3 mm) region. 
• For hard metal samples, the thickness should be between 0.5-2mm; for soft metal alloy ~2 mm, and for polymer and hybrid composites ~ 1-3 mm.

(Left) for hard material (i.e., Fe, Ti); (Middle) for soft metal (i.e., Al alloy); (Right) for polymer and hybrid composites

Compression Sample Preparation

• Sample dimension: After changing the tensile parts to compression parts, the physical distance between jaws can move from 10 to 15 mm. Unless the objective of measurement are features with > 30 micron (such as: the forming of cracks at certain loads or general shape deformation), it is not recommend to submit samples at maximum size (~ 15 mm tall and ~ 30 mm in diameter). The sample should have at least one flat surface to be properly mounted on the flat jaw substrate, an adhesive tape may be taped on the side. You will have to calculate the force load based on the surface area and target pressure, so a cylindrical or cubic testing region is preferred. 
• For small samples (1-5 mm), we do provide a spacer that is 10.06 mm tall. The jaws and spacers are all made of steel that can hold up to ~ 800 MPa.
• For test(s) requiring high load(> 700 MPa, i.e., 2 kN over 0.5 x 0.5 cm surface area): In order to protect the jaws, and provide accurate testing results, please provide the spacers (upper and lower) made of the same or harder materials. (If using the same material, best practice will be to machine something with the shape below).

Microtest conditions:

There are few conditions can be controlled using the Microtest software:

• Speed of motor movement range from 0.1 mm/min to 1 mm/min. A slower test speed would create less force relaxation after achieving target load. i.e., set a compression load to 1000 N, after the motor stops moving, the measured force may reduced to 950 N after 10 min for slower motor movement, or 900 N after 10 min for faster motor movement. It is critical for hard material.
• Control the measurement by: time (of motor movement), extension distance (move the jaw by a distance, most used in tensile mode), absolute height (move the jaw to a distance), load (move the jaw to a load, most used in compression mode)
• After reaching the target, you have the options to: stop measuring the force, continues measuring the force, moving the jaw to keep load constant (to against relaxation), move to the next load or cycling to the set load. (The measure and constant load can be set as automatic runs in S&S software)
• Temperature control: separate heating and cooling units to the upper and lower jaws. Temperature range from -20 to 180 °C.