Lub luag haujlwm ntawm txhuas hauv tooj dag yog dab tsi

Lub luag haujlwm ntawm txhuas hauv tooj dag yog dab tsi?

Lead yog txhob txwm ntxiv rau tooj dag feem ntau los txhim khomachinability(qhov yooj yim ntawm kev txiav, drilling, threading, los yog shaping cov khoom ntawm machining txheej txheem). Nws cov haujlwm tseem ceeb suav nrog:

Lubrication thaum lub sij hawm machining: Cov hmoov txhuas muaj nyob hauv qhov sib cais, cov khoom muag muag hauv cov tooj dag matrix. Thaum cov khoom raug txiav, cov khoom siv lead ua no ua cov roj nplua nyeem hauv, txo kev sib txhuam ntawm cov cuab yeej txiav thiab cov khoom ua haujlwm. Qhov no txo cov cuab yeej hnav, txo qis txiav quab yuam, thiab tiv thaiv "chip welding" (qhov twg hlau shavings ua raws li lub cuab yeej, ua rau tsis zoo).

Txhim kho chip tsim: Lead txhawb cov tsim ntawm luv luv, nkig chips uas tawg yooj yim thaum lub sij hawm machining, es tsis ntev, stringy chips uas yuav clog machinery los yog ua puas lub workpiece nto.

Enhanced nto tiav: Txo kev sib txhuam thiab tswj nti tsim ua rau smoother, ntau meej nto zoo ntawm cov khoom siv tooj dag.

Qhov tseem ceeb, cov hmoov txhuas tsis zoo txhim kho tooj dag cov khoom siv kho tshuab (xws li, lub zog, ductility) thiab tej zaum yuav txo qis corrosion nyob rau qee qhov chaw. Nws ntxiv yog nruj me ntsis rau kev ua tau zoo nyob rau hauv siab - ntim machining daim ntawv thov (xws li li qub, fittings, fasteners).

Cov khoom dab tsi hloov cov hlau lead hauv cov hlau lead - dawb tooj dag?

Txhawm rau ua raws li cov cai ntawm ib puag ncig thiab kev noj qab haus huv, lead- tooj dag dawb siv lwm cov hlau alloying los ua kom cov hlau lead ua haujlwm tsis muaj tshuaj lom. Cov kev hloov pauv uas muaj xws li:

Hloov Element(s)	Mechanism & Zoo	Tej kev siv
Silicon (Si) + Manganese (Mn)	Cov ntaub ntawv nyuaj, brittle intermetallic theem (xws li, Mn₂Si) uas ua raws li cov chips tawg. Txhim kho machinability thaum tuav zoo corrosion kuj thiab lub zog.	Cov kav dej fittings, valves, automotive Cheebtsam.
Bismuth (ib)	Mos, tsis tshua muaj - melting- taw tes cov ntsiab lus uas precipitates raws li cov khoom sib cais, ua raws li cov hmoov lead lub lubricating nyhuv. Bi tsis yog- lom thiab tsis cuam tshuam cov khoom siv dag zog.	Precision machined qhov chaw, hluav taws xob connectors.
Tin (Sn) + Zinc (Zn) Optimization	Kho cov tooj dag matrix los txhim kho nti fragmentation. Tin kuj tseem txhim khu kev tiv thaiv corrosion (tshwj xeeb tshaj yog nyob rau hauv daim ntawv thov dej haus).	Cov ntsuas dej, cov khoom siv hauv hiav txwv, khoom noj khoom haus- qib.
Tellurium (zeeg)	Cov ntaub ntawv nkig Te- muaj cov khoom sib txuas uas pab txhawb kev tawg. Muab cov machinability zoo heev tab sis yog siv rau hauv daim ntawv thov niche vim tus nqi siab dua.	Siab -qhov tseeb aerospace lossis cov khoom siv hluav taws xob.

Piv txwv ntawm Lead-Free Brass Alloys:

C69300 (Si-Mn tooj dag): Muaj ~ 2.5-3.5% Si thiab ~ 1.5-2.5% Mn, dav siv hauv cov kav dej thiab cov khoom siv tsheb.

C68700 (Bi- tooj dag): Muaj ~ 1.0-2.0% Bi, haum rau kev kub ceev machining ntawm fittings thiab fasteners.

C70600 (Naval tooj dag, lead-dawb variant): Tin- txhim kho (1.0-1.5% Sn) rau corrosion kuj nyob rau hauv marine ib puag ncig.

Cov kev xaiv no tswj cov tooj dag qhov zoo hauv lub cev (zoo formability, corrosion kuj, nqi-effectiveness) thaum ua tau raws li kev coj noj coj ua thoob ntiaj teb- cov qauv dawb. Qhov kev xaiv ntawm cov hlau yog nyob ntawm machining yuav tsum tau, kawg - siv ib puag ncig, thiab kev tswj xyuas.