Heat Treatment Validation - Titanium (6Al 4V) for 2 hours @ 700 Deg C

[achorste]

Hi all,

(First thread I've created although some of your previous threads have been very beneficial - for that I offer many thanks!)

I have been asked to validate our heat treatment process. We currently have one air furnace in which we heat treat titanium (6Al 4V) for 2 hours @ 700 Deg C & air cool.

Has anyone else had to do a similar validation? I have full access to our labs so micro & mechanical testing isn't an issue. Really I suppose I need to know the key points I'll have to cover.

Many thanks for any help you could give.

[BradM]

Welcome to the Cove!

Validation is one of those words that have broad connotation, and may mean different things to different people. It's important to find out from your customer/regulatory body what they are expecting.

I would surmise there should be two components. One of which would be to qualify the heat treat process. This should involve running a temperature profile survey. This is putting thermocouples in the furnace, running to the use temperature, and determine the uniformity, overshoot, etc.

Second, you may need to determine effective heat treating on the product. This may involve hardness tests or various other tests.

We really need some more information regarding the industry, your requirements, and who is asking you to perform this validation.

Hope that gives you a general starting place.

[Benjamin28]

Brad has given some good advice and is correct, we would need more information to give you any focused, valuable advice. What are you hoping to validate? As Brad said, this word can cover a wide range of things which may be validating the process via hardness testing, or...validating that the equipment, etc, conforms to AMS 2750 or other specifications.

[harry]

Second, you may need to determine effective heat treating on the product. This may involve hardness tests or various other tests.

At times you get different readings for similar parts from the same batch but placed at different parts of the furnace.

[Dale D. Barnes]

Here is our process for Aluminum parts.

Tpaq Data Recorder is placed on rack with test parts and 12 thermocouples. The Thermocouples are at all locations on the rack and two of them are air only the rest are imbeded in the parts. The rack is then ran in normal production (ex. continuous oven rack is placed with normal production racks)
The data paq records all temperatures and time at temp. in all zones along with the quench cycle and the age oven. We have specific standards that have to be met for the system to pass.

We also do thermocouple verifies on a monthly basis for the systems.

Every batch (we do a lot of parts) gets hardness tested, tensile strength tested, and mechanical test.

The datapaq and thermocouple verifies the oven.

The hardness test, tensile test, and mechanical test verify the batch.

Hope this helps.

Dale

[achorste]

Hi all, thanks for your help.

I have been tasked with "validating our process" of which heat treatment is one part. Without further clarification (which I am currently seeking) I would assume this would cover both qualifying the heat treatment process and its effectiveness on the parts in question.

We do full matallurgical analysis of every part range at proof stage as part of the validation we submit to our customer however, no-one has validated each process individually. This has come about after a customer audit.

The company makes forgings for medical implants (hips, knees etc.)

[BradM]

So then is this an FDA process?

Sorry to keep posing questions, but the term validation is awfully broad. In addition, there sounds like there may be several processes to validate.

1. Start with some specification of what the management intent (system requirements) is/are for the process. For example, we will perform XXX process. We will use an oven designed for YYY; the parts will then be tested with ZZZ. The acceptance criteria is AAA, and so on.

2. Then you will write the test for the requirements. Generally you will have some portion that will cover adequate installation of the equipment. Is the equipment installed properly, correct environment, correct voltage, etc.? If it is a gas furnace, what pressure/flow does the burner require? Are all the safety requirements met?

3. Next, you will generally evaluate the equipment operates as it was intended. Does the equipment do what it was purchased to do? Test the uniformity requirement of the furnace, possibly test the exposure time.

4. Finally, you will evaluate the equipment performs adequately for your stated process. This is production-related. Training will play into this step.

Those are the general steps. It will be difficult for us to say "hey, here's what you should do" without knowing what specification you are working against, what the process requirements are, etc.

Whoever suggested/requested/requiring the validation should be able to give a little more light as to exactly what needs to be done.