Dab tsi yog qhov nyuaj hauv kev tswj qhov tsis zoo ntawm cov hlau 3D luam ntawv pwm?

1. Qhov sib txawv ntawm qhov sib txawv vim cov khoom shrinkage thiab thermal stress
Thaum lub sij hawm 3D luam ntawv txheej txheem, cov ntaub ntawv hlau mus los ntawm ib qho khoom -kua- theem khoom hloov. Lub thermal expansion coefficient thiab shrinkage tus nqi yog qhov tseem ceeb uas cuam tshuam qhov tseeb ntawm qhov ntev. Piv txwv li, siv cov khoom siv uas feem ntau siv:

Stainless hlau (zoo li 316L): Tus nqi ntawm qhov txias txias yog kwv yees li 4%. Yog tias qhov kev kho rov qab tsis ua tiav thaum lub sijhawm ua qauv, 100mm ntev pwm tuaj yeem txo mus rau 96mm, uas yog sab nraud ntawm qhov kam rau ua ntau yam ntawm ± 0.1mm.
Titanium alloys (xws li Ti-6Al-4V) txo qis los ntawm kwv yees li 2%, tab sis thermal kev ntxhov siab tsim tau sai dua, uas tuaj yeem ua rau muaj kev sib hloov yooj yim, tshwj xeeb tshaj yog nyob rau hauv cov tsev nrog cov phab ntsa nyias lossis cantilevers.
Kev nyuaj siab: Txhawm rau nrhiav qhov tseeb shrinkage tus nqi, koj yuav tsum siv cov cuab yeej rov qab engineering xws li Geomagic Control X. Koj kuj yuav tsum tau siv cov mis "paub qhov loj me=tsim loj ÷ (1-shrinkage rate)" thaum lub sij hawm ua qauv. Piv txwv li, pwm ua los ntawm stainless hlau yuav tsum yog 4.2% loj (100mm → 104.2mm), thiab pwm ua los ntawm titanium alloys yuav tsum yog 2.04% loj (100mm → 102.04mm). Kev taw qhia kev them nyiaj thev naus laus zis kuj tseem tuaj yeem daws teeb meem nyuaj thaum Z-axis shrinkage tus nqi yog 10% siab dua XY axis hauv SLM cov txheej txheem.

2. Improving process parameters: the technique for balancing energy density and layer thickness
Rau cov hlau 3D luam ntawv kom raug, cov yam ntxwv zoo li laser zog, scanning ceev, thiab txheej thickness yuav tsum tau tswj nyob rau hauv ib txoj kev sib koom tes. Ib qho kev hloov pauv hauv qhov ntsuas yuav ua rau muaj teeb meem loj.

Tsis txaus lub zog ceev: Yog tias lub zog laser qis dhau los yog qhov ntsuas nrawm nrawm dhau, cov hmoov tsis yaj tag nrho, uas ua rau tsis tiav fusion defects. Qhov no tsis muaj zog rau kev khi ntawm cov khaubncaws sab nraud povtseg thiab ua rau qhov loj ntawm cov khoom tsis ruaj khov.
Lub zog siab ceev: Yog tias lub zog laser hloov pauv ntau dua 5%, lub pas dej molten splashes forcefully, thiab cov kua hlau hloov mus rau hauv ib puag ncig ntawm cov hmoov uas tsis tau yaj. Qhov no ua rau qhov chaw tsis sib xws thiab hloov qhov loj.
Xaiv lub thickness ntawm cov khaubncaws sab nraud povtseg: Ib txheej thickness ntawm 0.1 hli tuaj yeem ua rau cov khoom siv tau zoo dua, tab sis cov qauv yog qhov tseeb thiab qhov roughness Ra loj dua 5 μ m. Ib txheej tuab ntawm 0.03-0.05mm tuaj yeem ua rau roughness Ra<3 μ m, but it will take more than three times longer to print.
Case Study: Ib lub tuam txhab aviation siv SLM tshuab luam ntawv turbine hniav. Lawv siv cov kev sim orthogonal los nrhiav qhov zoo tshaj plaws ua ke ntawm cov tsis: lub zog laser ntawm 300W, scanning ceev ntawm 1200mm / s, txheej thickness ntawm 0.05mm, thiab ib tug cross scanning txoj kev (nyob ib sab cov khaubncaws sab nraud povtseg scanned raws X / Y axis). Qhov ntev kam rau ua tau zoo tswj nyob rau hauv ± 0.05mm, ua raws li aerospace qauv.

3. Qhov tseeb ntawm cov khoom siv: los ntawm calibrating hardware mus rau kev tswj cov lus tsa suab
Lub hauv paus ntawm lub cev rau kev tswj qhov loj yog cov khoom siv precision. Yuav kom ua tiav qhov no, peb qhov chaw yuav tsum ua haujlwm ua ke los txhim kho: cov qauv siv tshuab, cov lus tsa suab, thiab cov sensors.

Levelness ntawm lub platform: Yog hais tias lub tshuab luam ntawv tsis yog theem, cov khaubncaws sab nraud povtseg yuav tsis yog tib lub thickness, uas tej zaum yuav ua rau qhov ntev yog "tuab ntawm ib sab thiab nyias ntawm lwm yam." Txhawm rau kom paub tseeb tias qhov kev nyeem ntawv sib txawv ntawm tsib qhov chaw (plaub fab ntxiv rau qhov nruab nrab) ntawm lub platform tsawg dua lossis sib npaug li 0.05mm, koj xav tau lub ntsuas ntsuas qhov tseeb rau 0.01mm.
Muaj qhov chaw nruab nrab ntawm cov ntsia hlau txhuas thiab cov kev taw qhia rail: Yog tias qhov sib nrug loj dhau, lub taub hau luam ntawv yuav txav mus deb dhau. Yog tias koj hais kom nws txav 10mm, nws yuav txav 10.02mm tiag tiag. Txhawm rau pom qhov sib txawv ntawm qhov yuam kev, koj yuav tsum tau luam lub phaj tiaj tiaj nrog ntau lub qhov me me (5 hli inch thiab 20mm sib nrug) thiab siv cov cuab yeej ntsuas kev sib koom tes. Tom qab ntawd, koj tuaj yeem txhim kho qhov teeb meem los ntawm kev siv lub cuab yeej software's "electronic gear ratio."
Calibration ntawm lub laser qhov chaw txoj kab uas hla: Yog hais tias koj teem lub qhov chaw txoj kab uas hla tsis ncaj ncees lawm (piv txwv li, yog hais tias nws yog tiag tiag 0.1mm tab sis qhov kev pab cuam hais tias nws yog 0.08mm), koj muaj peev xwm muaj "dhau hlawv" los yog "nyob rau hauv burning." Sau ib txoj kab ncaj nraim uas ntev 10 hli, tom qab ntawd ntsuas qhov dav dav thiab muab piv rau qhov program hais. Koj yuav tsum tau kho qhov yuam kev yog tias nws ntau dua 0.02mm.
4. Kev tsim qauv ntawm kev txhawb nqa: nrhiav qhov sib npaug ntawm lub zog thiab yooj yim ntawm kev tshem tawm
Cov qauv txhawb nqa tsis yog tsuas yog "skeleton" uas ua rau tus qauv tsis hloov pauv, tab sis nws kuj tuaj yeem yog qhov ua rau muaj qhov yuam kev loj:

Ntau qhov chaw ntawm kev txhawb nqa: Yog tias qhov chaw nruab nrab ntawm kev txhawb nqa ntawm qhov raug tshem tawm (xws li 5mm cantilever) ntau dua 3mm, cov khoom tuaj yeem poob thaum luam ntawv, uas ua rau muaj qhov sib txawv loj.
Lub kaum sab xis txhawb nqa: Yog tias lub kaum sab xis ntawm qhov kev txhawb nqa thiab qhov qis dua 45 degree, tshem tawm cov kev txhawb nqa tuaj yeem yooj yim "rub" thiab hloov cov duab ntawm qhov, tshwj xeeb tshaj yog tias nws nyias -walled (thickness<2mm).
Tsis muaj zog txaus rau hauv qab ntawm qhov kev txhawb nqa: Yog tias hauv qab ntawm qhov kev txhawb nqa tsis yog 50% loj dua ntawm txoj kab uas hla ntawm sab saum toj, cov khoom tuaj yeem tig tau yooj yim vim qhov tsis sib xws.
Txoj kev tshiab los daws qhov teeb meem:
Siv cov txheej txheem topology optimization los ua cov qauv kev txhawb nqa uas muaj zog tab sis xav tau cov khoom siv tsawg dua; xav tau cov cuab yeej ntse xws li ultrasonic txiav hniav kom tshem tawm cov kev txhawb nqa thiab tsis txhob cuam tshuam los ntawm rauj hits. Los ntawm kev txhim kho kev txhawb nqa tsim, ib tus tsim pwm rau cov tsheb tau txhim kho qhov ntev ntev ntawm nyias- cov phab ntsa ntawm ± 0.2mm txog ± 0.08mm.

5. Kev Tswj Ib puag ncig: Qhov tsis pom qhov cuam tshuam ntawm qhov kub thiab av noo
Cov neeg feem ntau tsis xav txog yuav ua li cas ib puag ncig tej yam kev mob cuam tshuam rau qhov seem stability ntawm hlau 3D luam ntawv:

Kev hloov pauv hauv qhov kub thiab txias: Kev hloov pauv ntawm qhov chaw ua haujlwm kub ntau dua 5℃(piv txwv li, 25℃thaum nruab hnub thiab 18℃thaum hmo ntuj) tuaj yeem ua rau cov cuab yeej nthuav dav thiab cog lus, uas tuaj yeem ua rau me me drift. Koj yuav tsum tau nruab cov cua txias uas ua kom qhov kub ntawm 22 ± 2 degree.
Hmoov noo noo nqus: Yog tias cov hmoov hlau muaj ntau dua 0.1% noo noo, luam ntawv yuav tsim pores, uas yuav ua rau qhov ntev tsis ruaj khov. Muab cov hmoov agglomerated tso rau hauv 80 mesh sieve thiab qhuav hauv qhov cub 80℃rau 2 teev.