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posted by janrinok on Tuesday September 03 2019, @10:45PM   Printer-friendly
from the don't-break-the-brakes dept.

Arthur T Knackerbracket has found the following story:

More than many other auto parts, brake discs are subject to repeated mechanical loads. As a result of this continual abrasion, they produce fine particulate matter, which pose a substantial environmental burden. Now, however, a new coating process developed by the Fraunhofer Institute for Laser Technology ILT and RWTH Aachen University can significantly reduce this impact. By using "Extreme High-speed Laser Material Deposition", known by its German acronym EHLA, it has proved possible to provide brake discs with an effective protection against wear and corrosion in a procedure that is both fast and economic.

Traditional coating processes such as electroplating or thermal spraying. The problem with such processes is that they do not produce a metallurgical bond between the cast iron and the protective coating; moreover, they are expensive and use a lot of materials.

Now, however, a new process avoids these drawbacks. Developed by Fraunhofer ILT in Aachen, together with the Chair for Digital Additive Production DAP at RWTH Aachen University, it is known as Extreme High-speed Laser Material Deposition (EHLA).

[...] Coatings produced with conventional processes have pores and cracks. With the EHLA process, the coating remains intact and therefore provides longer and more effective protection for the component. This increases service life and prevents early failure as a result of damage to the surface of the brake disc. Moreover, the process is suitable for a wide range of materials. Therefore, it is possible to select an environmentally friendly coating for each specific application.

The EHLA process is a new process variant on the well-known laser material deposition, which has proved highly successful in areas such as the repair of turbine blades. EHLA does, however, have a number of decisive advantages. With the EHLA process, the powder particles of the coating material are melted directly in the laser beam, rather than in a melt pool on the surface of the component. Since the melt pool now is fed by liquid drops of material rather than solid particles of powder, the coating process is much faster, rising from the 0.5–2 meters per minute with conventional laser material deposition to as much as 500 meters per minute.

This also substantially reduces the exposure to heat of the material being coated. Unlike conventional laser material deposition, where the heat affected zone can have a depth of one or more millimeters, thermal exposure with the EHLA process remains in the micrometer range. This enables the use of entirely new material combinations such as coatings for aluminum or—as with the brake discs—cast-iron alloys.


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  • (Score: 3, Informative) by JoeMerchant on Tuesday September 03 2019, @11:56PM (14 children)

    by JoeMerchant (3937) on Tuesday September 03 2019, @11:56PM (#889324)

    There's acoustic signature analysis - if you have a rotation index (typically a hall effect sensor) you can ensemble average the repetitive sound coming from the bearing (while dramatically reducing the background noise) and look for changes in the sound the bearing is making much more sensitively - essentially hear it whine early enough to do something about it before it causes serious damage.

    Or, you can do like my pickup truck 3000 miles after the shop monkeys replaced my brake discs and did a shit packing job on the wheel bearing - no detected signs of a problem until, while driving in the rain, the right front wheel seizes and slides for about 20' at about 45mph - then it breaks loose and starts wearing down the spindle, but... places to be... did manage to drive it to the appointment and home without needing a tow, almost 5 miles total.

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    🌻🌻 [google.com]
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  • (Score: 2) by RS3 on Wednesday September 04 2019, @01:47AM (2 children)

    by RS3 (6367) on Wednesday September 04 2019, @01:47AM (#889345)

    Ugh. This is why I do all my own work.

    Way back in the days of front drum brakes, during a state inspection I was aghast at watching a grease monkey pop my grease cap, pull the cotter pin, unscrew the nut, and pull the whole wheel and drum as an assembly, and not being careful with the outer bearing. I guarantee they knocked tons of crap onto the spindle before jamming the drum / wheel back on. Short drive home, completely clean and re-pack the wheel bearings. Sometimes the anuses would do both front wheels.

    But you've given me an idea... thanks...

    • (Score: 0) by Anonymous Coward on Wednesday September 04 2019, @01:52AM (1 child)

      by Anonymous Coward on Wednesday September 04 2019, @01:52AM (#889347)

      And when they overtighten the castle nut and your bearings seize 1/2 mile away.

      • (Score: 2) by RS3 on Wednesday September 04 2019, @02:07AM

        by RS3 (6367) on Wednesday September 04 2019, @02:07AM (#889353)

        Yeah, it's worth checking that before driving away from the place.

  • (Score: 2) by Reziac on Wednesday September 04 2019, @04:14AM (10 children)

    by Reziac (2489) on Wednesday September 04 2019, @04:14AM (#889374) Homepage

    Oh, I can do better than that... I bought a used F350 that had lately been rebuilt end to end. Factory drop-in transmission, receipts and everything. So I went about my business, which at the time was towing a heavy trailer cross-country a dozen times, and put about 20,000 miles on it, uphill both ways. Not a single hint anything was wrong, no noise, tranny never got over 160F, fluid looked fine. But on that last trip, I noticed it slipping a bit on a steep hill... by the time I got home it was slipping a lot. Off to the shop and it actually ceased to function IN their parking lot. Drove in, had to push it into the bay.

    So they get it apart and the ENTIRE thing is packed solid with shavings. As in practically no room for the fluid, I swear it was lubed solely with metal shavings, it was like pudding. And clear down at the arse end, they found the culprit: a bearing some yahoo at the factory had put in upsidedown.

    Now, normally this sort of problem fails within about 5000 miles, so is discovered within warranty. But this was Ford's super-duper extra-heavy transmission that could take a lot of abuse, so it didn't fail til it was well out of warranty. And I became the proud owner of a variety of interesting paperweights with bizarrely carved cogs, and an entertaining bill for more than I paid for the whole truck. (Well, even so it was still a bargain... the hard part was getting the gobbets of flesh off the wallet.)

    --
    And there is no Alkibiades to come back and save us from ourselves.
    • (Score: 2) by JoeMerchant on Wednesday September 04 2019, @07:57PM (5 children)

      by JoeMerchant (3937) on Wednesday September 04 2019, @07:57PM (#889668)

      Fun... the lesson is: check your fluids often (might have noticed the sparklies in there...)

      Says the guy who hasn't checked oil levels on any of his 5 engines in the last 2 months...

      --
      🌻🌻 [google.com]
      • (Score: 2) by Reziac on Wednesday September 04 2019, @08:51PM (4 children)

        by Reziac (2489) on Wednesday September 04 2019, @08:51PM (#889688) Homepage

        LOL -- yeah, I suppose if one checked it thoroughly...

        ... and I understand the hasn't-checked issue, heh... then again, there are gauges and they work...

        --
        And there is no Alkibiades to come back and save us from ourselves.
        • (Score: 2) by JoeMerchant on Thursday September 05 2019, @01:52AM (3 children)

          by JoeMerchant (3937) on Thursday September 05 2019, @01:52AM (#889790)

          Well, if you pull a dipstick and it has sparklies in the fluid...

          As for gauges... I suppose, but with oil they tend to indicate that a problem has already happened.

          --
          🌻🌻 [google.com]
          • (Score: 2) by Reziac on Thursday September 05 2019, @02:37AM (2 children)

            by Reziac (2489) on Thursday September 05 2019, @02:37AM (#889814) Homepage

            True... tho when I bought the truck my mechanic dude checked it, and it looked fine, and it got checked with oil changes, and was always fine... Not sure I wouldn't have been looking at a full rebuild anyway, just sooner, given any abnormal wear makes more abnormal wear.

            Of course no one checks that kind of thing every time they drive... we have better expectations of our modern tech, perhaps not always justified. :(

            --
            And there is no Alkibiades to come back and save us from ourselves.
            • (Score: 2) by JoeMerchant on Thursday September 05 2019, @03:05PM (1 child)

              by JoeMerchant (3937) on Thursday September 05 2019, @03:05PM (#890054)

              I have better expectations of our modern tech, unfortunately I also have worse expectations of our modern technicians. In the romanticized "good old days" the machine was a flimsy piece of junk, but the technician tended (more often) to completely understand it, how to properly diagnose and maintain it, so at least you got the meager lifetime out of it that was expected.

              As I recall, we sold our '69 Camaro because it was "nearly worn out" at 70,000 miles.

              --
              🌻🌻 [google.com]
              • (Score: 2) by Reziac on Friday September 06 2019, @03:24AM

                by Reziac (2489) on Friday September 06 2019, @03:24AM (#890371) Homepage

                Good point; I've observed the same -- old cars were more repairable, but as they approached that 100k mark, they needed more repairs and might get beyond repair if let go even a little bit. (Trucks not so much, being made for abuse, if only by overkill in everything.) I wouldn't call the old cars flimsy (metal parts were much heavier back then), but tolerances and lubricants have greatly improved, and there's less access for grit to get in, so I expect the reduced wear on moving parts has a lot to do with it.

                Electronics, tho... my old mechanic mostly worked on newish cars; my '78 F100 was probably the oldest vehicle he serviced, just the reality in SoCal that there's a lot of vehicle churn due to long commutes, so old ones are not common. Anyway... when something went wrong with those newish cars, they'd spend 12 hours hooked to the computer and half the time they still didn't get diagnosed; all very expensive and frustrating for everyone. Meanwhile when something broke on my old truck it was obvious -- I could just point at the leaking or busted part and say look here, fix that, and it was quick and relatively cheap. (Only retired at 34yrs/240k miles cuz when I moved circumstances conspired to prevent taking both trucks. The "new" truck has more miles on it, and will probably go another 20 years.)

                And then there's what used to be a fender-bender; now what with all the plastic and crumple zones and unibody, the same ding totals the new car. So it goes both ways. Back in the mists of time I had a '63 Olds F85 and I regularly carried heavy stuff on the roof without damaging it. (Apparently I mistook it for a truck.) Try that now without a roof rack and see what happens! Well, unless you drive a Lada....

                https://www.youtube.com/watch?v=o3z5LOnii-4 [youtube.com]

                Crazy Russians. :D

                --
                And there is no Alkibiades to come back and save us from ourselves.
    • (Score: 2) by RS3 on Saturday September 07 2019, @04:14AM (3 children)

      by RS3 (6367) on Saturday September 07 2019, @04:14AM (#890832)

      Ouch! Didn't opt for a used trans?

      I've rebuilt them too. Nowadays most trans problems are solenoids, switches, connectors sometimes.

      • (Score: 2) by Reziac on Sunday September 08 2019, @03:45AM (2 children)

        by Reziac (2489) on Sunday September 08 2019, @03:45AM (#891164) Homepage

        I needed it back in service yesterday if not sooner; if it were a C4 easy to find/cheap/quick to do, but E40D not so much (apparently it's a super-duper variant too), and used might not have been progress, if not already rebuilt. (At the time I was expecting it to tow 12,000 pounds over mountain passes with 8% grade, so... reliable first.) So did a rebuild at a good shop, had it back in 4 days. But not quite how I'd expected to spend the money...

        --
        And there is no Alkibiades to come back and save us from ourselves.
        • (Score: 2) by RS3 on Monday September 09 2019, @03:17AM (1 child)

          by RS3 (6367) on Monday September 09 2019, @03:17AM (#891519)

          May be worth finding a good used one to have in standby?

          I love the line: "uphill both ways". Thanks for the chuckle.

          • (Score: 2) by Reziac on Monday September 09 2019, @04:06AM

            by Reziac (2489) on Monday September 09 2019, @04:06AM (#891532) Homepage

            Welcome :) I tellya, some o'them mountain passes tilt no matter which way yer goin'!!

            Much as I'd like to have a whole extra truck in standby... a couple grand outlay vs that it'll probably go 200k miles before it needs another rebuild (it has 250k on it and is like a new truck), which at my present rate of consumption is about 65 years...

            --
            And there is no Alkibiades to come back and save us from ourselves.