Ndi ma castings ati omwe amalimbitsa wosanjikiza ndi wosanjikiza, ndi ma castings ati omwe amalimba ngati phala, ndipo ndi ma castings ati omwe amalimba pakati?

Panthawi yolimba ya kuponyera, nthawi zambiri pamakhala magawo atatu pamtanda wake, womwe ndi malo olimba, malo olimba, ndi malo amadzimadzi.

Malo olimba ndi malo omwe "olimba ndi amadzimadzi amakhala pamodzi" pakati pa malo amadzimadzi ndi malo olimba. M'lifupi mwake amatchedwa solidification zone wide. M'lifupi wa zone solidification ali ndi chikoka chachikulu pa khalidwe kuponyera. Njira yolimba ya kuponyera imachokera ku m'lifupi mwa malo olimba omwe amaperekedwa pamtanda wa kuponyera, ndipo amagawidwa kukhala wosanjikiza-ndi-wosanjikiza kulimbitsa, phala kulimbitsa, ndi kulimba kwapakatikati.

Tiyeni tiwone mawonekedwe a njira zolimba monga kusanjikiza-ndi-wosanjikiza ndi kulimbitsa phala.

Kukhazikika-ndi-kusanjika: Pamene m'lifupi mwa chigawo cholimba ndi chopapatiza kwambiri, chimakhala cha njira yolimba-yosanjikiza. Kukhazikika kwake kumalumikizana mwachindunji ndi zitsulo zamadzimadzi. Zitsulo za malo ocheperako olimba zimaphatikizapo zitsulo zoyera (mkuwa wamafakitale, zinki zamafakitale, malata a mafakitale), ma eutectic alloys (aluminiyamu-silicon aloyi, ma aloyi apafupi ndi eutectic monga chitsulo chotuwira), ndi ma aloyi okhala ndi mawonekedwe ocheperako (monga chitsulo chochepa cha carbon). , aluminium bronze, mkuwa wokhala ndi kristalo yaying'ono. Milandu yachitsulo yomwe ili pamwambayi ndi ya njira yolimba-yosanjikiza.

Madziwo akalimba kukhala olimba ndikucheperachepera, amatha kuwonjezeredwa ndi madziwo mosalekeza, ndipo chizoloŵezi chotulutsa shrinkage chobalalika chimakhala chaching'ono, koma mabowo okhazikika amasiyidwa mu gawo lomaliza lolimba la kuponyera. Mitsempha ya shrinkage yokhazikika ndi yosavuta kuchotsa, kotero kuti katundu wa shrinkage ndi wabwino. Ming'alu ya intergranular yomwe imayambitsidwa ndi kutsekeka kotsekeka kumadzaza mosavuta ndi chitsulo chosungunula kuti chichiritse ming'alu, kotero kuti zopangazo zimakhala ndi chizolowezi chochepa cha kutentha. Imakhalanso ndi luso lodzaza bwino pamene kulimbitsa kumachitika panthawi yodzaza.

Kodi phala coagulation ndi chiyani: Pamene coagulation zone ndi yotakata kwambiri, imakhala ya phala coagulation njira. Zitsulo zomwe zili m'dera lalikulu lolimba zimaphatikizapo ma aloyi a aluminiyamu, ma aloyi a magnesium (zitsulo zotayidwa zamkuwa, zotayidwa za aluminium-magnesium, ma aloyi a magnesium), ma aloyi amkuwa (malata amkuwa, mkuwa wa aluminiyamu, mkuwa wokhala ndi kutentha kwakukulu kwa crystallization), ma aloyi achitsulo-carbon. (high carbon steel, ductile iron).

Kuchuluka kwa malo olimba achitsulo, kumakhala kovuta kwambiri kuti thovu ndi inclusions muzitsulo zosungunula ziyandama ndikuchotsa panthawi yoponya, komanso zimakhala zovuta kudyetsa. Castings amakonda kutentha kusweka. Pamene ming'alu ichitika pakati pa makhiristo, sangathe kudzazidwa ndi zitsulo zamadzimadzi kuti ziwachiritse. Pamene mtundu uwu wa alloy umalimba panthawi yodzaza, mphamvu yake yodzaza imakhala yosauka.

Kulimbitsa kwapakati ndi chiyani: Kukhazikika pakati pa malo ocheperako olimba ndi malo olimba kwambiri kumatchedwa gawo lapakati lolimba. Ma alloys omwe ali mdera lapakati lolimba amaphatikiza chitsulo cha kaboni, chitsulo chokwera cha manganese, mkuwa wapadera komanso chitsulo choyera. Makhalidwe ake odyetserako, chizolowezi chophwanyidwa chamafuta ndi mphamvu yodzaza nkhungu zili pakati pa kusanjikiza-ndi-kusanjika ndi njira zolimbitsira. The ulamuliro wa solidification wa mtundu uwu wa kuponyera makamaka kusintha magawo ndondomeko, kukhazikitsa yabwino kutentha gradient pa mtanda gawo la kuponyera, kuchepetsa solidification m'dera pa kuponya gawo mtanda, ndi kusintha solidification akafuna kuchokera pasty solidification kuti wosanjikiza. -ndi-wosanjikiza kulimba kuti mupeze castings oyenerera.