Micro drilling help needed

[chris_wyrick]

My research and information from drill bit and autofeeding drill vendors are yielding conflicting information regarding necessary drill speed (RPM) and feed rate for my application. I need to determine the time required to drill through .090 inch thick Inconel 625 using a .028 inch DIA drill bit. Time needs to be ~3 seconds or less in order for my process to be feasible for production.

Can this be done with an automatic feeding drill assuming rigid mounting of both workpiece and drill?
Appreciate any response from someone well versed in drilling tiny holes in very hard metals(2205, 2507, Inconel 625).

Thanks

[Kelly_Bramble]

Maybe abrasive water jet... Other than that you need to engage manufacturers whom specialize in these exotics.

[chris_wyrick]

Water jet is not suitable for implementation into our line. Laser and EDM would be too expensive. Drilling seems to be the only route given our process.

Thanks for the response Kelly.

[Kelly_Bramble]

I am aware that when machining/drilling Inconel that tool wear is very accelerated. A drill may only last a few drilling operations before a tool change-out is required. It may turn out that physical drilling is not cost effective at all.

[chris_wyrick]

I am aware that when machining/drilling Inconel that tool wear is very accelerated. A drill may only last a few drilling operations before a tool change-out is required. It may turn out that physical drilling is not cost effective at all.

Given that this will only have to be done twice per shift or about every 4 hours, it will be well worth the money to replace a bit every single time a hole is drilled even if the bits cost $30+ each.

[tamer_usta]

Hi Chris,

I think it can be done in a cnc with autmatic feed. Kennametal has that small dia drill.It can be a bit expensive tool but 30$ is enough to process this dimenson. Cutting speed and feed will be provided by tool manufacturer.

[chris_wyrick]

Even in this case I think the drill bit will have to be replaced right? So it's pretty much the same

OK to replace bit every hole drilled, but I need to verify whether this can be done with an auto feeding drill, or if it would require larger machinery which would not be suitable for our production line.

Thanks

[ishmaeldada]

it seems to me that ECM can be feasible, this depends on your economics; how many parts do you intend to produce and how much they (or the assembly they go in) gives you in dollar terms. Compare this to the process cost (tooling, time, labor). The fact that special processes like EDM, ECM and laser are more precise and at times quick can make them a good choice. This benefit may override their disadvantage of cost. You have to make an analysis