Likarolong tse ntseng li tsoela pele ka potlako tsa Likoloi tse Ncha tsa Matla, litsamaiso tsa polokelo ea matla, le{0}}kabo ea matla a matla a phahameng, boleng ba likhokelo tsa copper busbar ke tsona tse thusang tsamaiso eohle ea motlakase. Joalo ka ha indasteri e hloka phetoho ho tloha "ho etsa khokahano" ho ea ho netefatsa "nako e telele ea bophelo, tahlehelo e tlase, le bofokoli ba zero," Medium Frequency Direct Current Inverter.Spot Weldere hlahile -e le tharollo e tloaelehileng ea indasteri. Leha ho le joalo, ho sebelisa bokhoni ba eona ka 'nete, kutloisiso e tebileng ea fisiks ea motheo le taolo ea ts'ebetso ke ea bohlokoa.
Tataiso ena e fana ka{0}kakaretso e tebileng ea tekhenoloji ea MFDC mabapi le koporo busbar welding, ho akaretsa thermal physics, full process parameters, different material joints, le{1}}tharollo ea mathata sebakeng.
Core Physics: Hobaneng ha Copper Busbar Welding e Hloka MFDC?
Koporo e fana ka phephetso e ikhethang ea ho hanyetsa welding ka lebaka la conductivity ea eona e phahameng haholo ea mocheso (hoo e ka bang $ 400 W/(m\\cdot K)$) le conductivity ea motlakase. Sena se bolela hore mocheso o hlahisoang nakong ea ho tjheseletsa o senyeha ka potlako ho lisebelisoa tse potolohileng le li-electrode, ho etsa hore ho be thata ho theha nugget e tsitsitseng ea weld.
Ho ea ka Molao oa Joule, $ Q=I^2Rt $, tlhahiso ea mocheso e itšetlehile haholo ka khanyetso ea ho kopana pakeng tsa li-workpieces, kaha ho hanyetsa ka bongata ($ R $) ea koporo e tlaase haholo.
Li-welders tsa khale tsa AC (50/60Hz) li na le bothata ba ho feto-fetoha ha maemo hona joale le libaka tsa ho feta{2}}tseo li bakang tshitiso ea nakoana ea mocheso. Bakeng sa koporo e nang le mocheso o phahameng haholo, khefutso ena e khutšoanyane e lumella mocheso hore o tsoe, hangata o fella ka ho phatsima ha holim'a metsi empa ntho e sa fellang kapa "e batang" ea weld (e tsejoang e le "shunted weld").
MFDC welder e hlola sena ka ho fetolela sejoale-joale ho maqhubu a phahameng (hangata 1000Hz) le ho hlahisa haufi le-DC ripple e phethahetseng{2}mofuta oa maqhubu a mahala. Kenyelletso ena e tsitsitseng, e tsoelang pele ea matla e tiisa:
- Instantaneous Heat Balance: Maqhubu a holimo a lumella millisecond{0}}taolo ea boemo, ho hlahisa mocheso o lekaneng ho etsa nugget pele mocheso o ka qhala matla.
- Thepa e tsitsitseng ea Nugget: Theko e boreleli ea DC e boloka mocheso oa letamo o qhibilihisitsoeng, ho fokotsa ho lelekoa (spatter) le ho netefatsa hore ho na le junifomo, weld e tebileng.
- Sebaka se Ametsoeng ke Mocheso o Fokotseng (HAZ): Matla a tsepamisitsoe haholo ho sehokelo sa weld, se bohlokoa bakeng sa lipakete tsa betri tsa NEV moo mocheso o feteletseng o ka senyang lisele tse haufi kapa ho koala.
Taolo ea Ts'ebetso e Felletseng: Ho Tseba Tatelano ea Welding
Ho fumana weld{0}ea boleng bo holimo ba copper busbar ho hloka ho fetang feela ho seta ea hajoale; e kenyeletsa -methati e mengata e hlophisitsoeng.
1.Pele-Tokisetso ea Weld Surface: Mohato oa Bohlokoa oa Pele
Libaka tsa koporo ka potlako li etsa lera la oxide le nang le khanyetso e phahameng. Ho chesoa ka holim'a lera lena ho lebisa molokong o sa tsitsang oa mocheso le spatter e feteletseng.
- Ho Hloekisa ka Mechini: Sebelisa borashe ba terata kapa sekhopho se setle ho tlosa lera la oxide, u lebisitse ho khoasolla holimo ($Ra$) ea hoo e ka bang $1.6\\mu m$.
- Ho fokotsa lik'hemik'hale: Hloekisa sebaka sa ho cheselletsa ka joala ba indasteri kapa acetone ho tlosa oli le litšila tse ka etsang carbonize le ho baka porosity ka har'a weld.
2. Litlhophiso tsa Paramethara tse khothalelitsoeng (Mohlala: 3mm+3mm Koporo e Hloekileng)
Molao-motheo o akaretsang oa ho cheselletsa koporo ke "Hona joale, Nako e Khutšoane, Matla a Phahameng."
| Mothati oa Ts'ebetso | Paramethara | Recommended Range | Mosebetsi le Mabaka |
| Hlakola |
Matla a Electrode (Khatello) |
3.5 - 5.5 kN | E netefatsa kamano e haufi-ufi le ho tsitsisa khanyetso ea pele. |
| Weld | Welding Current (I) | 18 - 25 kA | Ho hlokahala hore ho be le boemo bo phahameng ba hona joale ho hlōla conductivity e phahameng ea mocheso oa koporo. |
| Weld | Nako ea Weld (t) | 150 - 300 ms | E bolokiloe e khuts'oane ho fokotsa tahlehelo ea mocheso; hangata e fanoa ka makhetlo a 2-3. |
| Tšoara | Ho Tšoara Nako (Khatello) | 100 - 200 ms | E boloka khatello nakong ea ho tiisoa ha nugget ho thibela likheo tsa shrinkage le ho phatloha. |
3. Tsamaiso ea Electrode
- Boitsebiso: Sehlopha sa 2 (CuCrZr) kapa Sehlopha sa 3 (CuBe2) ke maemo. Bakeng sa li-busbar tse teteaneng haholo, litšepe tse refractory joalo ka Tungsten kapa Molybdenum ka linako tse ling li sebelisoa ho eketsa khanyetso le ho tsepamisa mocheso.
- Geometry: Karolo e kholo ea radius (mohlala, R50{4}}R100 dome kapa khoune e sephara ea sefahleho) e khethoa ho laola boima ba hona joale le ho fokotsa indentation.
Li-Welding tse sa Tšoaneng: Lisebelisoa tse tsoetseng pele tsa NEV
Li-welders tsa MFDC li ipabola maemong a rarahaneng a ho kopanya a tloaelehileng tlhahisong ea betri ea NEV:
- Koporo + Aluminium:Sena se phephetsa haholo ka lebaka la ho thehwa ka potlako ha brittle Intermetallic Compounds (IMCs). Taolo e nepahetseng ea MFDC e lumella weld e laoloang e lekanyetsang botenya ba IMC ho li-micrometer tse 'maloa, ho netefatsa matla a mochini le ts'ebetso ea motlakase.
- Koporo + Nickel/Stainless Steel:Kaha Nickel le Stainless Steel li na le khanyetso e phahameng ho feta koporo, mocheso o fetoha ka tlhaho ho ea sebakeng se phahameng- sa khanyetso. Tharollo e kenyelletsa ho sebelisa Li-Electrode tse sa Tšoaneng: eleketrode e phahameng-e hanyetsanang (mohlala, Molybdenum) ka lehlakoreng la koporo le eleketrode e tloaelehileng ea CuCrZr ka lehlakoreng la nickel ho leka-lekanya mocheso oa tlhaho.
Tlhahlobo ea Boleng le Maemo a Indasteri
Boleng ba weld bo tlameha ho netefatsoa ho sebelisoa mekhoa ea tlhahlobo e kotsi le e sa senyeng, hangata e lebisang litekanyetso tse thata tse kang IPC-A{3}}610 (Acceptability of Electronic Assemblies) le maemo a ikhethileng a likoloi joalo ka QC/T 413.
| Tekanyetso Metric | Tlhokahalo e Tloaelehileng | MFDC Tshebetso |
| Matla a Mechini | Teko ea Peel: Nugget bophara ($ D$) $\\ge 5\\sqrt{t}$ | Ho lumellana ho phahameng; "konopo" e hloekileng ea ho hula-mokhoa oa ho hloleha. |
| Ts'ebetso ea Motlakase | Teko ea ho Kena ha Mocheso (E Reiloe Hona Joale) | Mocheso oa khokahanyo o nyoloha $\\le 5^\\circ C$ ka holimo ho mocheso oa busbar. |
|
Ponahalo/Dimensional |
Botebo ba Indentation | E tlameha ho ba $< 15%$ of the thinnest sheet thickness. |
| Metallurgy | Sebopeho sa Nugget | Sebopeho sa lijo-thollo tse tšoanang; porosity e nyane kapa -mapetso a manyane. |
Ho-Tharollo ea Mathata a Sebaka: Tataiso e sebetsang ea Mathata a Tloaelehileng
Leha ho na le lisebelisoa tse nepahetseng, mefuta e fapaneng ea ts'ebetso e ka baka liphoso. Mona ke tafole e sebetsang bakeng sa baenjiniere ba masimong:
| Bofokoli bo Lemohile | Motso oa Sesosa Analysis | Tharollo e Sebetsang |
| Electrode Sticking/ Ho khomarela | Pholiso e sa lekaneng kapa bongata bo feteletseng ba hona joale. | Increase cooling water flow rate (target $>6L/min$); sebelisa bophara bo boholo ba sefahleho sa electrode. |
| Spatter e Feteletseng / Ho Lelekoa |
Matla a sa lekaneng a li-electrode (khatello) kapa ho kopana ho fokolang holim'a metsi. |
Eketsa Matla a Squeeze/Pre{0}Weld Force; etsa bonnete ba hore li-workpiece li bataletse ebile li hloekile. |
| Letheba le ntshofetseng/le chesitsweng | Oxidation ea bokaholimo kapa nako e feteletseng ea weld. | Ntlafatsa ho hloekisa pele{0}litšepe; sebelisa nako e khuts'oane ea weld ka li-pulses tse ngata; nahana ka tšireletso ea khase ea inert. |
| Matla a Weld a sa tsitsang | Khanyetso e feto-fetohang ka lebaka la ho roala ha li-electrode. | Etsa kemiso e tiileng ea ho apara li-electrode (resurfacing) le ho nkela sebaka. |
Qetello
Katleho eaMFDC spot weldingbakeng sa busbars koporo hase feela marginal; e emela phetoho ea mantlha ea bokhoni ba tlhahiso. E rarolla mathata a tlhaho a boleng bo phahameng ba koporo, ho fana ka weld e phahameng e ts'epahalang haholo (ka tloaelo ho 99.9% + chai), ho boloka matla a bohlokoa (ho fihlela ho 30% ho fokotseha ho bapisoa le AC), le ts'ebetso e felletseng ea ts'ebetso.
Bakeng sa lienjiniere tsa NEV le liindasteri tsa motlakase, ho sebelisa tekhenoloji ea MFDC ha e sa le boikhethelo-ke ntho e hlokahalang bakeng sa ho fumana likhokahano tse phahameng- tsa motlakase tse phahameng{2}} tse batloang ke litsamaiso tsa sejoale-joale.
