Oscillatory effectiveness for a given period of time eliminates the research of stress of remains of aluminium alloy test specimen

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Summary: Eliminated stress of remains of aluminium alloy component to undertake exploration to oscillatory effectiveness for a given period of time, choose rectangular and sectional aluminium alloy test specimen to regard research as the object. The kind that carries to load is prefab to its leftover stress, fall to be stimulated to its in certain bearing condition next brace up, experimental result makes clear, stimulate brace up later the leftover stress numerical value of test specimen got reducing mixing leveling. The is versed in oppose launchs nonferrous metal component part oscillatory effectiveness for a given period of time of the article considered to provide experiment basis. Keyword: Oscillatory effectiveness for a given period of time; Leftover stress; Stress of remains of aluminium alloy foreword is a kind of of interior of component of consist in metal internal stress that balances oneself, the ingredient that produces leftover stress is very much [1, 2] , but Baconian rise, basically have 2 factors, it is hot action firstly, bring about refrigeration inhomogenous and generation internal stress, have commonly cast, solder to be waited a moment with heat treatment; It is the action of force secondly, bring about metallic surface layer or in-house plasticity to be out of shape [3] , have metallic cutting treatment commonly, to load. The existence of leftover stress affects the performance characteristics of mechanical spare parts directly, reduced the working intensity of the spare parts, the measure that affected a part is stable, the exhaustion that quickens a spare parts is destroyed [4, 5] . Accordingly, the existence of leftover stress is right for metallic spare parts, it is a kind of potential risk undoubtedly. As a result of the harmful sex of leftover stress, people passes natural effectiveness for a given period of time, all sorts of methods such as hot effectiveness for a given period of time and oscillatory effectiveness for a given period of time undertake elimination the processing of leftover stress, here " eliminate " implication is mixed to reduce however leveling remains stress, be not the elimination on firm sense. Oscillatory effectiveness for a given period of time is saved with its installation cost, waste time can be little and get effective to wait for an advantage quickly more and more the favour that gains people. Current, oscillatory effectiveness for a given period of time applies in black metal domain relatively extensive [6, 7] , if be opposite cast-iron an oscillatory ageing treatment that waits with carbolic steel weldment, the effect is more apparent. Use oscillatory effectiveness for a given period of time at dropping the application that with remains of component of leveling nonferrous metal stress studies however example and document are scarcer [1] . As nonferrous metal, especially the aluminium alloy wide application in the project, the research of this one domain causes the attention of people more and more. The article tries to pass the test of test specimen of sectional to the model aluminium alloy, will study oscillatory effectiveness for a given period of time eliminates the leftover stress in aluminium alloy material, it is oscillatory effectiveness for a given period of time thereby this technical application provides experiment basis at nonferrous metal domain. The purpose of to load of test specimen of Nextpage of design of 1 test program is for prefab and leftover stress, accordingly, the size of load F decides at two elements: It is F firstly must be make data yields in order to achieve, namely the meet an emergency when to load should be more than 3581 × 10-6, it is F secondly cannot too big, destroy in order to shun stuff. Of course, set out from the angle of this experiment, below the premise that does not destroy data, increase load as far as possible, so that get greater leftover stress. In the experiment, with WE-300 fluid pressure type universal test machine applies to load to carry on one's shoulder or back to test specimen, suffer force to nod the midpoint in test specimen, make test specimen is made pure bend be out of shape, in to load process, with the volume that ES-1 standard dynamometer measures, monitor with appearance of YJR-5 resistor meet an emergency stick a circumstance of meet an emergency of the dot. Next watches are result of test of test specimen to load, expressing medium meet an emergency is the metabolic value of way of standard of monitoring point of test specimen midpoint. 1.

Stress of 3 tests remains uses bore law to measure the leftover stress of aluminium alloy test specimen, this is a kind of more mature method [8, 9] , its are basic the thought is one alveolus is gotten on the member that has leftover stress, make be released as a result of partial stress inside the adjacent region of aperture and the meet an emergency with corresponding generation, measure these meet an emergency, via can reaching bore manages original stress after conversion. Because bore law is a kind of ruinous measurement technique, according to experimental requirement, dope some nods the leftover stress value of oscillatory around, such ability are made quite, and it is very difficult that leftover stress is measured 2 times in same point, it is this to be able to be solved by the following method, if the graph is shown 3 times, if want to measure A to nod the leftover stress value of oscillatory around, the surface of the same cross section that nods in A controls each apart 10mm to be in dot of choice A ′ and A ″ to nod, the circumstance of leftover stress change that the leftover stress value that can measure A ′ dot and A ″ place respectively through oscillatory around so will come to sentence A to nod, the basis of law of this one party is: It is we had done leftover stress to determine to the test specimen before to load, the leftover stress value that discovers its surface is roughly equal, field of cloth of approximate Yu Jun; 2 it is to load means it is central place suffers test specimen carry, bring about test specimen to make bend be out of shape, on the coping that the same horizontal stroke that reason nods in A carries a scale at 3 o'clock A, a ′ , the leftover stress value after A ″ is uninstalled is roughly equal; 3 it is the fundamental that accords with bore law. 1.

Effectiveness for a given period of time of vibration of 4 oscillatory ageing treatment is in what proper time brings to bear on near the resonance frequency of component part or structure to stimulate with vibrator namely brace up, reduce the goal with leveling remains stress in order to achieve. To all pledging for fine grain, different bearing form, its natural frequency is different, what use in this experiment is the mechanical model that 2 end secure, its are first-order natural frequency can press type gets: By on the first-order natural frequency that type can get the system after two end secure test specimen makes an appointment with 436Hz. When the experiment, of the experiment stimulate Zhen Pin rate to should be gotten by signal generator sweep around 436Hz, move stress value to succumb at material not quite 1/3 ultimate, the join of experiment instrument is shown 4 times like the graph, stimulate around resonance dot brace up time is controlled commonly control in 15min. Nextpage2 test result and data processing 2.

1 experiment chooses 3 to nod on the 1 test specimen that grows in 800mm, if pursue,5 are shown. Oscillatory around place measures gotten A, b, the result of the leftover stress that C3 nods is shown 7 times like the graph. Be being reduced from what stress of oscillatory around remains can see in the graph is apparent. 2.

2 experiments choose 5 to nod on the 2 test specimen that grow in another 800mm, if pursue,6 are shown. Oscillatory around place is measured A, b, c, d, the edge that E5 nods advocate if the leftover stress result of stress direction pursues show 8 times. 3 analysises and discuss (2) is experimenting 1 in, brace up before the limits is worth region of leftover stress is - 7.

2~34.

2MPa, and brace up hind turn into - 25.

6~5.

3MPa, brace up hind than brace up before the value region of leftover stress dropped 25.

4% . Experimenting 2 in, brace up before value region is - 12.

6~31.

9MPa, brace up hind value region is - 16.

0~11.

0MPa, brace up hind than brace up before the value region of leftover stress dropped 39.

3% . By afore-mentioned analysises knowable, leveling of oscillatory effectiveness for a given period of time the leftover stress of test specimen, and the effect is more apparent also. 4 conclusion can see from inside the experiment above and analysis: To ageing treatment of vibration of aluminium alloy component, can more apparent ground is reduced and stress is worth leveling remains, can conclude then going out to use technology of oscillatory effectiveness for a given period of time at component of other nonferrous metal also is feasible. Of course, when the project uses this technology actually, still remain at accumulating experience further, choose each parameter reasonably. CNC Milling CNC Machining