Its intensity jumps over the hard alloy of all sorts of brands tall, the possibility that produces crackle in process of drill rod solder is less. In producing a course actually, razor blade of alloy of the tall hardness that is used at finish machining or superfinishing, tall wearability (wait like YD15, YG3X, YN10) crackle of easy when drill rod solder generation. My company is in charge of soldering the production of the knife and quality management, solder knife generation crackle is the influence solders one of main problems of knife quality. The article was elaborated solder the account that the knife produces crackle and avoid measure, undertook from much angle detailed ground is analysed, solved long-term worry effectively to solder the problem that the knife produces. 1 solder the razor blade of influence hard alloy that the mechanism that knife crackle forms and type 1) heat to form crackle to hard alloy and steel (arbor) hot coefficient of expansion differs bigger, and the heat conduction function of alloy also relatively cutter hub material is poor, if heat quickly when solder,can produce very great internal stress, make bit soldering layer place thermal stress passes to bring about bit to burst apart greatly. Because this solders,temperature control is being made an appointment with be more than solder dissolve to nod 30 ～ 50 ℃ . Chosen solder its melting point should under arbor melting point 60 ℃ , the blaze when soldering should by fall to heat equably up slowly warm-up undertakes soldering, because chamfer of this requirement knife and bit solder side are formed,agree. Local overheat can make the difference in temperature of bit itself or razor blade and arbor bigger (big more as serious as thick razor blade) , thermal stress will make blade point bursts apart. Be opposite first when requirement warm-up so arbor warm-up, if bit and arbor heat together,answer blaze of shuttlecock of around left and right sides undertakes heating, can avoid quantity of heat to concentration causes local overheat and produce crackle so. The affects knife chamfer figure that appearance of 2) knife chamfer forms to crackle and arbor solder side abhorrent or differ bigger, form enclosed or half enclosed groove form, easy cause solder side to pass with solder layer too much big, shrinkage is abhorrent after expanding as a result of heat, stress is caused easily also in bit weld too big, form burst apart. The welding line intensity that satisfying use place need asks to fall, reduce the area of face of drill rod solder as far as possible. The influence that 3) refrigeration forms crackle to hard alloy solders medium or after soldering, undertake cooling or quickness refrigeration and welding flux dehydrate are undesirable, can make bit produces blowout and crackle be well versed in. Because this requirement solder has good dehydration sex. Solder hind cannot be put in refrigeration of the quickness in water absolutely, in wanting to be put in pink of lime, asbestine, sand to wait slow refrigeration. Heat preservation is controlled 6 hours in 300 ℃ after best delay is cold above cools along with furnace. The affects bit and knife chamfer interface that face of 4) knife bottom land has blemish to be formed to crackle is rough whole, if have reason of hole of black skin hemp, local imparity, make solder cannot form planar union, cause solder to distributing not divide evenly, such not only intensity of influence welding line and cause stress concentration, bring about bit to rupture, accordingly, bit wants abrade interface, to bit knife groovy solder side should be cleaned clean. In the process cooperating with bit in chamfer of mill razor blade, requirement razor blade extends arbor bearing part to be more than 0. 5mm, if bit reachs arbor bearing share too big or arbor bearing part is weaker, can make cutting tool is soldering to pulling force bears in the process and arise rupture phenomenon. The influence razor blade that 5) razor blade heats 2 times to be formed to crackle is after drill rod solder, makings of red copper drill rod does not have complete cram aperture, appear individually empty solder, some cutting tool are in process giving heat, bit falls down on arbor, because this needs 2 times to heat, come so, binder Co burns caustic badly, WC grain is grown, bring about bit crackle directly likely. The feature that 2 welding stress cause crackle (figure of A) (b) (c) (d) appears on razor blade of 1 hard alloy crackle, because welding stress is exorbitant,the under certain circumstance is, the intensity that exceeded hard alloy razor blade and of generation. Soldering when cutting tool, the high Hc of cutter hub should be more than bit height Ht3 times. Be like Hc/ht, after solder, cause alloy razor blade easily to rupture (1a) seeing a picture; Be like Hc/ht<3, generation of hard alloy surface layer pulls stress, appear easily also crackle (1b) seeing a picture; When Hc/ht=4 ～ 5 when, hard alloy surface layer does not have remarkable stress, reason produces crackle not easily, although have flaw not apparent also (1c) seeing a picture; When Hc/ht<8, soldering arise on the layer all cloth load. And alloy razor blade curves generation of direction of ply of edge alloy razor blade to pull stress, soldering the power that the intensity of the layer exceeds alloy itself distributings more complex, because not be,go up in a face joint, and be in two, 3 or the union on 4 faces. In addition, when hard alloy heats quickly and cooling quickly, because quantity of heat distributings not all, produce remarkable instantaneous stress possibly. When heating quickly, hard alloy is outer press press stress, suffer among pull stress. Allow more than heat when speed, the sightless crackle with respect to likelihood occurrence crackle or interior (2a) seeing a picture. When hard alloy solders, fast refrigeration also is very dangerous, below this kind of circumstance, outer on can appear pull stress, and cause alloy occurrence crackle (2b) seeing a picture. (A) heats quickly the crackle of generation (the crackle that B) fast refrigeration produces pursues 2 CNC Milling
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