Does it make sense to define a self-live of titanium powder (TiCP) with an average grain size of 150 µm (mesh 90)? Powder is stored in airtight containers and after opening the container it will be used in days. For bar, sheet or other product forms nobody would think of it but for powder we...
Currently I have the problem that we have some metallic zirconium parts that show shadowa /corrosion on the surface. Therefore I am looking for a way to mild way to etch/ pickle the parts. Up to now we did not succeed in processing. Does anyone have experience in surface treating zirconium...
@metengr: thanks for you reply. up to now i did not think about continious casting vs ingot. I will try to follow up on this issue. may be this gives more infromation. what would you expect - more problems during polishing with materaial from ingot melting or from the continious casting. I...
here a recent discussion we had - are there more or less nonmetallic inclusion in a bar or in a plate visible when you are doing an evaluation assumed that the same melting procedure for the primary and secondary melting.
basically my point was that I would not expect a difference but a guy...
actually we are doing only light laser marking - when examined microscopically at 100x you will see discoloration of the surface. the reason for mot going up with the power is that we do not want to damage the surface too much - the marking shall visible, not influencing them mechanical...
we already do line marking - the problem is that we need to do passivation due to corrosion issues but if we do Nitric 3 for 30 minutes the lasermarking is gone....
is there anyone with experience on passivation of martensitic & austenitic steels that need to be passivated and laser marked. I do know the procedured according to ASTM A 380 / A 967 but this conflicts with laser marking. I am lookin g foreward to get some input.
Regards
Frank
sorry metengr your post is not helpfull. I know about the possiblities of a proper failure analysis. it is not the intention of this thread. the intention is to figure out whether markings on the surface might influence fatigue live.
@TVP yes we have quiet some testing without markings and...
... the interpretation of the writing instrument with the soft graphite tip is correct. Nevertheless I have heard that no such markings shall be on titanium surfaces...
we are currently testing parts made from Ti6Al7Nb - which should behave similar to Ti6Al4V for fatigue life properties. Actually we got an early failure that was unexpected and now we are looking for explanations.
One thing that bothers me is the fact that somebody made pencil marks on the...
Currently I am looking for fatigue data for Rex 734, UNS31675 according to ASTM F1586. As far as I found there is not much data published on this material. Does anybody have a good idea where to find fatigue and other data?
Thanks
Frank
sorry for beeing unprecice. I'm looking for the stuff similar to what is used for the semiconductor. Silcon metal.
sorry for the confusion.
Regards
Frank
Silicone powder supply
We are currently in a project where silicone powder is used as an processing agent. For this project I need to find a good, relieable supplier who can deliver Si-powder 99.9% pure in grain size -325 mesh or -60 mesh. Does anybody have a good idea where to get it...
do you want to know a specific alloy? Normally I get good results when looking at MatWeb. They give all material identification numbers but not all eupopean names...
Regards
Frank
@EdStainless: We have been using brand new high precission collets with a polished edges. the samples have a roughness of 0.3micormeters - which corresponds to former N5. as mentioned above I've already tried to use a thin foil... but again it tells me that we already were in the right direction...
Again thanks for all contributions!
@metalguy
I've tried several ways to avoid the friction by lubrication. actually non of them worked so far. We do have a special high moly grease and that doesn't change anything. I've also tried to work compleately "degreased" but that didn't help as well...
thank'x for the advice. first of all - I'm sure we do have some fretting and or corrosion on the samples. the problem is that we do test up to 480 MPa load on the test specimens. I think there is some mircromotion between the samples and the collets. there is no way to fix it more tightly. as a...
I'm currently testing Ti6Al4V on the rotating beam fatigue test setup. the problem is that quiet some samples do break just at the end of their fixation. Actually all specimens were produced according to the relevant standards. We have been testing some other materials like TiCP, 316L Stainless...
