So how did you heat treat the frame without the rest of it distorting? Usually heat treat then machine.
Interesting discussion about heat treating. I'm not sure what alloy Yamaha uses for their frames, but the Japanese
manufacturers don't stray too far from one another. Honda uses 7075-0 for their frames. This alloy has a tensile
strength of 40,000 psi which is about the same as 6061-T6. One of the bennies of using 7075 in an untempered
state, is you don't have to worry about strength loss due to weld repairs or modifications. It is generally accepted
when welding Aluminum alloy, that the area adjacent to the weld will have a "0" temper. That's a considerable loss
of strength from a "T6" state, but no loss from a "0" state.
Some of the AF conversions are being done by people that have little to no knowledge of materials and/or welding
skills. Trying to weld 6061 -T6 pieces to a 7075-0 frame is a recipe for disaster if the proper post weld processes
aren't followed.
Long story short, I can weld away on my 7075-0 frame without worrying about heat treating afterward. If you used
7075-0 alloy for the replacement parts, I bet the same is true for that Yamaha.
dogger
7075 - No.
Not in use in the welded structure that is the frame. Of Any motorcycle that I am aware of. But, there may be 'some' out there............
I assume you are the 'Dogger' I've had P.M contact with in the past?
Certainly, Most of the materials used in Japanese frame making Will be a variant of 7*** series materials. Though, there will be a mixture - plenty will have some 6*** and / or 5*** series materials. Generally, plate, and 'std' section type tube shapes. And 'other' materials.
The majority of Aluminium used in many manufacturers, especially the Japanese, will be a proprietary 7*** 'Mix' that will not be disclosed. Indeed, many 'mixes' will not appear on Any standard aluminium materials 'alloying' listings.
Some (most) 7*** materials have been specifically developed to not require heat treatment after welding - the natural 'ageing properties' of the materials are accelerated over other aluminium alloys. So, they will regain most of the base metals properties without any 'heat treatment', or artificial ageing. Some can be subjected to post weld treatment, some, not (goes to show, 'hard and fast rules' are not so 'hard and fast', often re 7*** being listed as heat treatable, as is 2***, and 6****. Conversely, you have the Non Heat treatable materials, that some of which, Can be Heat Treated - notably some 4*** and 5*** series - more on that further on).
7005 has become perhaps the most common, relatively inexpensive aluminium alloy for welded structures - most notable bicycle frames. The material itself is affordable, and, it's properties of reconstitution of base material specs / age hardening, present a Very useful savings in not having to heat treat / manipulate the frames after welding.
It's thought, by many of us small fabricators / frame makers, that much of the proprietary 'mixes' of Japanese and European / British motorcycles, Are 7020, Or Near To 7020 - a lovely material, which the Poms make great use of.
7075 is one of the aluminium alloys that is generally described as 'un-weldable'. Well, it's surely weldable, but surely a great way to produce a 'widow maker' of a structure. Be it welded without further heat treatment, or with further heat treatment. Playing with 7075, in welded structures / fitments, is like Russian Roulette - with All six barrels loaded.
Some of the best information, put in layman's terms, with regards to welding, is to be found on various welding machinery companies sites, such as Lincoln, miller and ESAB.
The ESAB one is very easily used and understood:
http://www.esabna.com/us/en/education/knowledge/qa/index.cfmIt may behoove some to read the above short and simple - in scholarly / engineering terms - link.
With my reference to 'hard and fast rules'. They are often broken. Many, here if you are into bicycles, will see often frame specs advertised, especially with American made frames, of the frame being made from 6061 T6 Tubing. Now, often, that means exactly that, and Only that. The frames Are made of 6061 T6 tubing, but they are Not solution heat treated after welding, or artifically aged. Indeed, it would be better, in terms of cost, for the frames to be made from 6061 - 0 / annealed tubing, Then have them solution heat treated and aged. Why pay for more expensive tube, that will then need to be brought back to 0 - annealed condition, to then be solution heat treated, and artificially aged? Most of the '6061 T6 Tubed' frames, are just welded up, being 'tacked only' in the jigs, welded fully and then, twisted / manipulated to straightness. The manufacturers sure can't be accused of lying. This can be got away with, by various methods - overbuilding - generally by much thicker butt ends than really are required, or larger sized tubing, staged welding techniques and so on.
My aluminium swing-arms and frames, are welded fully 'in jig', so no distortion happens - and / or, the known distortion is accounted for in the materials and jigging. As well as timed / staged weld patterns. Nothing of mine, requires manipulation - bending and subsequent weakening - or machining, after the structure is 'un-jigged'. I then, artificially age the structures in 'jigs', made for this purpose.
Some, very light weight / minimal design items I make, Are fully solution heat treated and artificially aged - or simply time aged, if the material is better suited to that. 'Free standing' (dirt bike type, generally) Aluminium Swing Arms, for example. And my very thin sheet construction swing arms. And, when my swing arms Are heat treated, it is done, in 'jigs' specifically made for the purpose. My triangulated swing arms - generally, no, they are subjected to the process outlined in the previous paragraph. Unless, they are outrageously light gauge in their construction.
Frames such as Cannondales 6061 tubed items, that are built with their 'multiple pass welding' that is then linished to form the large radius joints / 'non joints' (to many of the public's perceptions) are Almost always fully solution heat treated and artificially aged after welding. As the massive heat build up from multiple passes and wide fusion zones / Haze areas, really dictates that it be done. As well as many stamped type frames - the stamping / pressings requiring the sheet to be in 0 / annealed condition.
When I see the various 'commercial' AF builders list the frames as 'heat treated', I regard such claims with a Very Large grain of salt. I seriously doubt that they are brought back to 0 / annealed, then solution heat treated and artificially aged - with the required manipulation / machining of the frames between steps. Unless, of course, they have seriously substantial heat treatment jigs made and in use.
When I have made full new cradles - which is all I've done since the very first Gen 1s I did in '97 - I've heat treated the cradles, be they just bent tubing, or my favourite indulgence, 'welded plate' cradles, both types with the mounts attached to them, prior to heat treatment. Then, carefully staged welding patterns, with optimum timed welds, jigging, and large contact areas, are used for the cradle fitment. No post welding heat treatment required. I've never had a failure, in 16 years of CR AF conversions. And far longer when it comes to various other TZ / RG, GSXR etc hybrids.
Further to my mentioning of 'hard and fast rules', if you read that ESAB listing, you'll see various 'contradictions' regarding welding rods / filler material. You'll see that the most common filler materials / rods - 4043 and 5356, come into the 'Non Heat Treatable category of materials. Yet, they can, and Are used in weldments that are to be heat treated. Weird, isn't it?
I don't use 4043 much at all, most of what I do, I use 5356. Both rods 'base alloying', being of Non Heat Treatable alloys. Yet, they present No problems with subsequent heat treatment of a build. Weird, again, according to the rules.
I Do stock, And use, another 3 variations of both 4*** and 5*** series rods for special purposes. And, quite often, a sheet or tube (when dealing with frame repairs - from written off frames of the same type) of specific material, will be guillotined / cut up, to give me a definitive, known source of welding rod. A few of the 'anomalies' amongst welding rods are mentioned / explained in the ESAB listing. As I said, it's a very useful thing for the layman, And professionals, alike. I have many types of such listings kept handy - near materials racks, and various machines / work benches in my workshop. Hey, I'm getting old, I'm Very busy, and I know it's easy to F*** up, even (or perhaps because of) my decades of experience. And, I spend much of my time away from the workshop, in the halls of education, lately. So, I am doubly cautious when I do get back into my workshop.
Yes, my postings may read as treatises, at times, but I try to make them accurate, and informative. I'm not here, or on any sites to make money - I am trying to help people with their projects and impart a bit of my knowledge, so they don't stuff up. There's been a few people, that I've helped - or who have read my postings, who have gone on to make money using my advice / ideas. Fair enough, when I've put it in the public arena. Not fair enough, when it's been in private, and a few p***s have claimed things as their own, to then make money off.
Dogger, I seriously doubt your donor frames are 7075 Aluminium Alloy. Perhaps you've just made a 'typo'?
