Aralin 1Pagpili ng TIG vs MIG para sa bawat joint: pamantayan para sa posts-to-baseplate, handrail joints, at infill barsInihahalintulad ang TIG at MIG para sa typical aluminum joints tulad ng posts sa baseplates, handrails, at infill bars. Tinatalakay ang access, appearance, deposition rate, at skill level upang gabayan ang proseso ng pagpili at parameter setup.
Process comparison: deposition and controlPosts-to-baseplate joint process choiceHandrail and infill bar joint examplesAccess, position, and appearance factorsCost, productivity, and rework trade-offsAralin 2Mga karaniwang aluminum welding defects: porosity, lack of fusion, hot cracking — sanhi at preventive actionsTinutukoy ang mga karaniwang aluminum weld defects tulad ng porosity, lack of fusion, at hot cracking. Nauugnay ang bawat defect sa mga sanhi tulad ng contamination, poor fit-up, o heat input, at inilalahad ang mga paraan ng inspeksyon at corrective actions.
Porosity causes, detection, and preventionLack of fusion from low heat or techniqueHot cracking and solidification controlUndercut and overlap on fillet weldsVisual and NDT checks for aluminum weldsAralin 3Mga welding sequences at techniques upang mabawasan ang distortion: tack strategy, stitch welding, alternating sidesIpapakita kung paano nababawasan ng welding sequence, tack placement, at bead pattern ang distortion sa aluminum. Sumasaklaw sa stitch welding, backstep techniques, alternating sides, at presetting parts upang labanan ang inaasahang shrinkage.
Tack weld spacing and size for restraintStitch and skip welding on long jointsAlternating sides to balance shrinkageBackstep technique on thin platePresetting and cambering parts before weldAralin 4Joint assembly at clamping fixtures: pagbabawas ng gaps, paggamit ng angle fixtures at backingIpinaliliwanag kung paano nakakaapekto ang joint assembly, fit-up, at clamping fixtures sa distortion at weld quality. Sumasaklaw sa pagbabawas ng gaps, paggamit ng angle fixtures, backing bars, at adjustable jigs upang panatilihin ang alignment sa multi-pass aluminum welding.
Fit-up tolerances and gap controlAngle fixtures for square and miter jointsUse of backing bars and backing stripsAdjustable jigs for repetitive assembliesPreventing movement during tack and weldAralin 5Mga uri ng current at polarity: AC vs DCEN vs DCEP at kailan gagamitin ang bawat isaIpinaliliwanag ang AC, DCEN, at DCEP para sa aluminum welding, na nauugnay ang polarity sa cleaning action, penetration, arc stability, at electrode heating. Sumasaklaw sa typical TIG at MIG setups, machine settings, at kung paano pumili ng polarity para sa iba't ibang joint types.
AC balance and cleaning action on aluminum oxideDCEN for specialized aluminum applicationsDCEP effects on tungsten heating and cleaningPolarity selection for TIG vs MIG processesMachine setup checks for correct polarityAralin 6Mga considerations sa pulse welding: benepisyo para sa heat input at control, kailan ilapatSumasaklaw sa mga prinsipyo ng pulse welding para sa aluminum, kabilang ang peak at background current, frequency, at duty cycle. Ipinaliliwanag ang mga benepisyo para sa heat input control, out-of-position work, thin sections, at kung paano pumili ng pulse programs o manual settings.
Pulse parameters: peak, background, frequencyBenefits on thin aluminum and gap bridgingUsing pulse for out-of-position weldsSelecting factory pulse programs on power sourcesManual tuning of pulse for specific jointsAralin 7Pagpili at flow rates ng shielding gas para sa aluminum weldingNagdedeskripsyon ng mga opsyon sa shielding gas para sa aluminum TIG at MIG, na nakatuon sa argon, helium mixes, at pagpili ng flow rate. Tumutugon sa nozzle size, gas coverage, draft protection, at troubleshooting ng porosity o sooting mula sa poor shielding.
Pure argon for most aluminum TIG and MIGArgon–helium mixes for thick sectionsTypical flow rates by process and nozzleGas lens, cup size, and stick-out effectsDraft shielding and leak troubleshootingAralin 8Interpass cleaning at oxide removal sa panahon ng weldingIpinaliliwanag kung bakit kritikal ang interpass cleaning sa aluminum, na nakatuon sa oxide removal, hydrocarbon contamination, at moisture. Inihahalintulad ang stainless brushes, scraping, at light grinding, at tinutukoy kung kailan at gaano kadalas maglinis sa pagitan ng passes.
Aluminum oxide properties and weld impactDedicated stainless steel wire brushingSolvent cleaning and degreasing stepsLight grinding and scraping without gougingCleaning frequency between weld passesAralin 9Typical parameter ranges: amperage, travel speed, electrode size, wire diameter examplesNagbibigay ng typical starting ranges para sa amperage, travel speed, electrode size, at wire diameter sa aluminum TIG at MIG. Binibigyang-diin ang pag-adjust ng parameters para sa thickness, joint type, at position habang iniwasan ang mga karaniwang setup errors.
Amperage ranges by material thicknessTravel speed targets for TIG and MIGTungsten diameter and tip preparationWire diameter selection for spray transferParameter adjustment for position changesAralin 10Heat sink at cooling strategies: chill bars, temporary clamps, controlled cooling pausesNagdedetalye kung paano nababawasan ng heat sinks, chill bars, at clamping ang distortion at burn-through sa aluminum. Sumasaklaw sa backing bars, copper shoes, cooling pauses, at water-cooled fixtures, na may gabay kung kailan payagan ang controlled heat buildup.
Chill bar materials and contact requirementsTemporary clamps to control fit-up and warpBacking bars and copper shoes for root supportPlanned cooling pauses between weld passesWater-cooled fixtures and safety concerns
