Cost of DLMS part in titanium

[tbuelna]

I just got quotes for having a part made in 6Al-4V titanium using DLMS. I was a bit shocked when I saw the two vendor's quotes, both of which were right around $4K for a single part. The part volume is around 6 cu.in. (~1lb), the part dimensions are around 3.5"x2"x2.5", the shape of the part is fairly simple (no cored passages or thin walls), and the only processing I asked for was to trim off any tabs/supports and give the parts a tumble finish (no dimensional inspection, NDI, HT or certs required). In production the part will be investment cast, but I need one or two samples of the casting for development work and I figured DLMS would be an economical method to produce them. Direct from a digital model with no tooling required, right?

It seems to me that the DLMS vendors know what it costs to get a sample part using conventional investment casting rapid prototype processes, like where the wax pattern is 3D printed, and they quote a price just below that. The most frustrating thing is that I can actually have the "cast" part machined from ti bar using a 4-axis CNC mill for about 1/2 the cost of what the DLMS vendors want.

Has anyone had a similar part made using DLMS? If so, was the price anywhere close to what I was quoted?

 

[KENAT]

Certainly the pricing I've seen for DMLS is very high, such that you'd only use it where it either allowed geometry that couldn't be created by almost any another method or offers some inherent capability/performance other methods don't have.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[ctopher]

Check around. You may get it lower. Some online companies farm it out to lower costs.
Our company is purchasing a DLMS printer that all sites can share. Unfortunately it will not be at our site.

Chris, CSWA
SolidWorks 14
SolidWorks Legion

 

[tbuelna]

KENAT-

Thanks for the reply.

As I noted, the price I was quoted by two vendors for a relatively simple part was extremely high, almost $4K/lb. While I appreciate that the DLMS process used for titanium requires the workspace to be purged with inert gas, and sintering titanium powder requires high inputs of laser energy, I still don't see how they get almost a 100x increase from the price of the raw material to the price of the finished part.

 

[ajack1]

What I don't understand is why it costs more to get it 3D printed in wax?

 

[JNieman]

The machines are not cheap, nor the resources to run them. Investment is high. Run time is also quite high for such parts. That's a lot of hours dedicated to one part. Even if you devalue "unattended" shop time for machines like this, the rates are still nothing to discard. While I'm a bit surprised (not very) at $4k, I also don't know what your part is. This is pretty much within my realm of expectations for titanium DMLS production.

DMLS "3D Printing" isn't the "easy button" that Makerbot et al make it look like with FDM.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD, Enovia V5

 

[tbuelna]

JNieman-

I did a bit research regarding the quotes I got for this particular part, and the number I came up with for machine time was around $400/hr. This does not seem totally unreasonable for a complex machine costing $750K or more. I typically pay shop rates of $150/hr for work done on a $250K CNC mill.

But as you noted, DLMS is still mostly suitable for limited applications.

 

[ornerynorsk]

Your quote actually seems right in the ballpark as to what I've been seeing. Now if you can wait another 10 years or so, the price will have dropped exponentially.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[tbuelna]

onerynorsk-

Don't laugh, but it's probably going to be close to 10 years when (or even if) this part ever gets into production. Right now it's a development part for an aircraft program and you know how they can drag out.

The production part will be an investment casting. It is a housing for a 37mm OD duplex angular contact bearing set with a four hole base flange similar to the picture below, except it is one-piece and has much thinner walls/sections (3mm).

One other thing I noted when I was researching the cost for a DLMS part was the price of titanium powder. One source I found online wanted $380/lb for 1.0kg qty. I can buy aerospace quality 6Al-4V bar in small qty for $50-60/lb, so the price for powder seems a bit steep. Thankfully I can machine the development parts from bar on a 4-axis CNC mill, which will cost far less than using DLMS. But on the bright side I learned quite a bit about DLMS going thru this process.

Regards,
Terry

 

[MikeHalloran]

I think you have to handle Ti powder in an inert atmosphere and practice super neat housekeeping so it doesn't ignite on you, so a high price doesn't surprise me all that much.


Mike Halloran
Pembroke Pines, FL, USA

 

[tbuelna]

Ti powder does not need to be maintained in an inert atmosphere at ambient conditions. However, titanium in a liquid state needs to be isolated from exposure to oxygen since it will rapidly oxidize. The DLMS machines designed to use titanium powder have the capability to back-purge the workspace with inert gas. The melting temp of titanium is also quite high, so the DLMS machines designed to fuse titanium require high-powered lasers. For example, one DLMS machine I found capable of fusing titanium used a 400W laser and cost over $800K. It's build rate with titanium was about 1 cu.in./hr.

 

[ornerynorsk]

30 years ago I was paying upward of $60 per lb for tungsten carbide eutectic powder, so powders are always much higher than bar stock. Seems about right.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.