2013年7月25日星期四

Synthesis of superhard materials exploration carbide anvil


Anvil proper use of
A) six anvil precise adjustment
    The processing of the press-cylinder cumulative error is critical. Some scholars believe that such adjustments can be set eccentric presses itself neutral, which can only say that when there is no way to remedy, especially the larger presses cumulative alignment errors will also increase. But when we can do it in the press processing within its design limits, do not relax with eccentric adjustment requirements.
Anvil and down, left and right, front and rear three groups should be adjusted to a central point, or shear forces will play a larger role.
    2) warm-up before starting the anvil
    Where have to be energized before starting Preheat 15min or longer, then formal synthesis. Experience has shown that it is important to improve the life of the top hammer way. Pressure working pressure generally 1/3 or so. Now there are more than one hour warm-up, it is no longer necessary for the proper warm-up to the micro-hot.
    3) set aside anvil pressure
    Before each stop, do not put pressure on the press all relieved, the pressure chamber opened. One day or several days after synthesis, a top hammer dozens, hundreds or thousands of times continuous heating, cooling, boost, buck. Thermal stress, compressive stress repeated the role, then suddenly the synthesis chamber open to its own release stress, often caused by the steel ring off the front edge of the top of the hammer head; even if no U-turn, life is not long.
This general reserve pressure gauge is about 20 ~ 30MPa.
    4) Synthesis of non-stop
    Some believe that the press after starting work, to a certain stage should be stopped to "rest." This view is very wrong, the problem is still to see the results. Once we advocate boot, unless a special machine, therefore, not free to stop. This is because it boost heating; cooling down, the whole process has resulted in a dynamic equilibrium. This dynamic equilibrium more stable life for the better improve anvil, this movement is not easy to obtain homeostasis, once diamond high yield, good quality and low consumption.
    5) heated anvil top plane may not have pyrophyllite powder
    It is very easy to happen in the event of burns easily anvil, causing small cracks, and finally to the top hammer to shatter.
    6) a reasonable plug
    I had mentioned previously prevent the "point" contact to "face" contact. Later, workers changed the whole steel plug, not combined with Molybdenum tube  I believe that this change is good, but with the changing cavity, plug the "face" should also be somewhat larger, otherwise they become a "point", while achieving its purpose. Large cavity in the study powder catalyst synthesized block begins with cavity much, much bigger plug plug, the authors suggested that with a small plug, and this opinion was not accepted, but then a small plug does have excellent practice sex, so quickly across the country, this is a good example. Plug cankered easy to burn anvil, with pyrophyllite powder is easy to burn anvil, all with out a reason.
    7) Cooling anvil
    Speaking before changing the steel ring design, enhanced cooling problem. But not too cold. Too cold will cause the rod temperature difference is too large, steady increases have affected the quality of diamond. Here again is the fuel tank cooling issues raised, the available copper coils; also used car water cooler, so that the whole system presses the temperature down to ensure the stability of the performance of the press, which in the hot summer or the South is more important .

没有评论:

发表评论