Silica Sol Binder Mu Investment Casting

Kusankha kwa silika sol ❖ kuyanika kudzakhudza mwachindunji roughness pamwamba ndi dimensional kulondola kwandalama castings. Zovala za silika sol nthawi zambiri zimatha kusankha silika sol ndi gawo lalikulu la silika la 30%. Njira yokutira ndiyosavuta ndipo ntchitoyo ndi yabwino. Panthawi imodzimodziyo, chipolopolo cha nkhungu choponyera chomwe chimapangidwa pogwiritsa ntchito zokutira chimakhala ndi mphamvu zambiri, ndipo kuzungulira kupanga zipolopolo kungathenso kufupikitsidwa.

Silica sol ndizomwe zimapangidwira m'madzi zomwe zimakhala ndi silicic acid colloid. Ndi polima colloidal njira imene kwambiri omwazikana silika particles sungunuka m'madzi. Ma colloidal particles ndi ozungulira ndipo ali ndi mainchesi a 6-100 nm. Thendondomeko yoyendetsera ndalamakupanga chipolopolo ndi ndondomeko ya gelling. Pali zinthu zambiri zomwe zimakhudza gelation, makamaka electrolyte, pH, sol concentration ndi kutentha. Pali mitundu yambiri yazitsulo zamalonda za silika, ndipo zomwe zimagwiritsidwa ntchito kwambiri ndi zamchere zamchere zamchere zomwe zili ndi silica 30%. Njira yopangira chipolopolo cha silica sol ndiyosavuta. Njira iliyonse ili ndi njira zitatu: zokutira, kupukuta mchenga, ndi kuyanika. Njira iliyonse imabwerezedwa kangapo kuti mupeze chipolopolo cha multilayer cha makulidwe ofunikira.

Pali njira ziwiri zopangira silika sol: kusinthana kwa ion ndi kusungunuka. Njira yosinthira ion imatanthawuza kusinthana kwa ion kwa galasi lamadzi losungunuka kuchotsa ma ion a sodium ndi zonyansa zina. Ndiye yankho limasefedwa, kutenthedwa ndi kukhazikika ku kachulukidwe kena kake kuti mupeze silika sol. Njira yosungunula imatanthawuza kugwiritsa ntchito silicon yoyera ya mafakitale (gawo lalikulu la silicon ≥ 97%) monga zopangira, ndipo pansi pa chothandizira, imasungunuka mwachindunji m'madzi mutatha kutentha. Kenako, yankho limasefedwa kuti lipeze sol silika.

Magawo aukadaulo a Silica Sol pa Investment Casting
Ayi.	Mapangidwe a Chemical (gawo la misa,%)		Zakuthupi				Ena
	SiO2	Na2O	Kuchulukana (g/cm3)	pH	Kinematic viscosity (mm2/s)	SiO2 Particl Kukula (nm)	Maonekedwe	Gawo Loyima
1	24-28	≤ 0.3	1.15 - 1.19	9.0 - 9.5	≤ 6	7-15	mumtengo kapena wobiriwira wopepuka, wopanda chodetsedwa	≥ 1 chaka
2	29-31	≤ 0.5	1.20 - 1.22	9.0-10	≤ 8	9-20		≥ 1 chaka

Ma castings omwe amapezedwa ndi silika sol kupanga njira amakhala otsika roughness pamwamba, mkulu dimensional kulondola ndi yaitali chipolopolo kupanga kuzungulira. Njirayi imagwiritsidwa ntchito kwambiri popangira ma alloys osatentha kwambiri kutentha, zitsulo zosagwira kutentha, zitsulo zosapanga dzimbiri, zitsulo za kaboni, zotayira zochepa, zotayira za aluminiyamu ndi zida zamkuwa.

Silica sol mwatsatanetsatane wotayika wax investment casting process ndi yoyenera kupanga mobwerezabwereza zigawo za mawonekedwe a ukonde kuchokera ku zitsulo zosiyanasiyana ndi ma aloyi ochita bwino kwambiri. Ngakhale kuti nthawi zambiri amagwiritsidwa ntchito popanga zing'onozing'ono, njirayi yakhala ikugwiritsidwa ntchito popanga mafelemu a zitseko za ndege zonse, zokhala ndi zitsulo zokwana 500 kgs ndi aluminiyumu mpaka 50 kgs. Poyerekeza ndi njira zina zoponyamo monga kufa kapena kuponya mchenga, zitha kukhala zodula. Komabe, zida zomwe zitha kupangidwa pogwiritsa ntchito kuyika ndalama zimatha kuphatikiza ma contours ovuta, ndipo nthawi zambiri zidazo zimayikidwa pafupi ndi mawonekedwe a ukonde, motero zimafunikira kukonzanso pang'ono kapena kusasinthidwa kamodzi.

Zigawo zazikulu za zokutira sera pakupanga ndalama ndi:
Pamwamba wosanjikiza silika Sol zomatira. Ikhoza kutsimikizira mphamvu ya pamwamba ndikuonetsetsa kuti pamwamba pake sichikusweka;
Wotsutsa. Nthawi zambiri zimakhala zoyera kwambiri za zirconium ufa kuti zitsimikizire kuti zokutira zili ndi zotsutsana zokwanira ndipo sizimakhudzidwa ndi chitsulo chosungunuka.
Mafuta. Ndi surfactant. Chifukwa zokutira za silica sol ndi zokutira zochokera m'madzi, kunyowa pakati pake ndi nkhungu ya sera ndizosauka, ndipo kuyanika ndi kupachika sikuli bwino. Choncho, m'pofunika kuwonjezera chonyowa kuti apititse patsogolo kupaka ndi kupachika ntchito.
Defoamer. Komanso ndi surfactant amene cholinga chake ndi kuthetsa thovu mpweya mu wetting wothandizira.
Woyenga tirigu. Iwo akhoza kuonetsetsa kuti mbewu kuyengedwa kwa castings ndi kusintha makina zimatha castings.
Zowonjezera zina:kuyimitsa wothandizira, chizindikiro chowumitsa, chotulutsa chokhazikika, ndi zina.

 

 

Kusankha kolondola kwa gawo lililonse la silika sol coating ndiye chinsinsi chotsimikizira mtundu wa zokutira. Zigawo ziwiri zofunika kwambiri zokutira ndi refractories ndi binders. Chiŵerengero chapakati pa ziwirizi ndi chiŵerengero cha ufa ndi madzi a zokutira. Kuchuluka kwa ufa ndi madzi a utoto kumakhudza kwambiri ntchito ya utoto ndi chipolopolo, zomwe pamapeto pake zidzakhudza khalidwe la kuponyera. Ngati chiŵerengero cha ufa ndi chamadzimadzi cha chophimbacho ndi chochepa kwambiri, chophimbacho sichidzakhala chokwanira ndipo padzakhala ma voids ambiri, omwe angapangitse pamwamba pa kuponyera kukhala kovuta. Kuphatikiza apo, chiŵerengero chochepa kwambiri cha ufa ndi madzi chidzawonjezeranso chizolowezi cha zokutira kuti ziphwanyike, ndipo mphamvu ya chipolopolocho idzakhala yotsika, zomwe zidzachititsa kuti chitsulo chosungunula chiwonongeke panthawi yoponya. Kumbali ina, ngati chiŵerengero cha ufa ndi madzi ndi chapamwamba kwambiri, chophimbacho chidzakhala chochuluka kwambiri ndipo madzi amadzimadzi adzakhala osauka, zomwe zimapangitsa kuti zikhale zovuta kupeza chophimba chokhala ndi makulidwe a yunifolomu ndi makulidwe oyenera.

Kukonzekera zokutira ndi gawo lofunikira pakuwonetsetsa kuti chipolopolocho chili bwino. Popanga ❖ kuyanika, zigawozo ziyenera kukhala zofanana omwazika ndi kusakaniza mokwanira ndi kuthiridwa wina ndi mzake. Zida zomwe zimagwiritsidwa ntchito popanga utoto, kuchuluka kwa zowonjezera ndi nthawi yolimbikitsa zidzakhudza ubwino wa utoto. Malo athu ogulitsa ndalama amagwiritsa ntchito zosakaniza mosalekeza. Pofuna kuonetsetsa kuti chovalacho chili ndi ubwino wake, pamene zigawo zonse za zokutira ndizo zowonjezera zowonjezera, zophimba ziyenera kugwedezeka kwa nthawi yaitali.

Kuwongolera kwazinthu za zokutira za silika ndi gawo lofunikira lowongolera. The mamasukidwe akayendedwe, kachulukidwe, yozungulira kutentha, etc. wa utoto ayenera kuyeza osachepera katatu patsiku, ndipo ayenera kulamulidwa mkati mwa zoikamo nthawi iliyonse.