Mechanical strength of various materials

[hackerdaz]

Posting results from tensile tests for 8 materials, mainly filled or modified. Tensile specimens printed using m200, 0.19 height, high infill. Tested but not shown is Black Magic (graphene filled), difficult to print, had to preheat the filament in order to use it without breaking, but in terms of mechanical strength is around 0.7kN at 1mm of displacement, then it brakes. The middle cross-section of the specimens is 4X10mm^2.

[Julia Truchsess]

The parameter that often interests me most is layer bond strength - is that addressed in your testing? Also, FWIW, I've read that thicker layers have high bond strength due to their carrying more thermal energy for welding to the previous layer as they exit the nozzle.

[hackerdaz]

Since it is an ongoing investigation, layer height effect will be considered at a later time. Up to now, I focused on the energy absorbance during impact loading.
The results of this post show the suitability of the specific materials for engineering applications considering deformation. I will also upload the impact characteristics of these materials.
I agree with you that thicker layers should have better interlayer adhesion due to higher thermal energy, so I'm trying to find a normative that tests layered material delamination, in order to quantify the effect, but I haven't come to a conclusion yet.

[Julia Truchsess]

Thank you for sharing your work and results here, it is much appreciated!

[hackerdaz]

It would not be possible to conduct such a research without z-temp, since the majority of the tested materials cannot be used with the stock v2 hotend.
I have finished the data analysis of the impact experiments. Cylindrical specimens with a diameter of 20mm and height 30mm were tested against impact loading. The velocity of the drop weight speed maintained constant at 4.6 m/s. In the following diagram the impact energy absorbance, as well as maximum impact force, are presented.
Specimen #, Material
1, CFPLA
2, Longchain
3, PLA/PHA
4, PCPLUS
5, Polymax
6, GWPP
7, Carbonium
8, ZGlass
9, Black Magic

[ChunkyPastaSauce]

This is awesome.   
For the force and displacement graphs, the initial length of the stretched portions of the materials the same between samples? If so, what was it?

[hackerdaz]

The initial length is between 10 and 12mm, depending on the way that the extensometer was attached to the specimen.

[ChunkyPastaSauce]

If you know which goes with which, the graph can be reformatted to standard stress-strain (normalize for initial area and length). Then additional data from the graph can be determined (toughness, resilience, youngs modulus, elongation before break, etc).  If you list initial length with the specimen, I can reformat if you'd like.

[hackerdaz]

I have all the required data to prepare a stress-strain diagram. I will upload it when it is ready.