ʻO nā mea wela o ka pahu metala ka helu heheʻe, ka wela kikoʻī, ka hoʻonui ʻana i ka wela, ka conductivity thermal, ka diffusivity thermal, ka pāhawewe wela a me ke kūpaʻa haʻalulu wela, ʻo kekahi o ia mau mea like me ka mea matrix, aʻo nā mea ʻē aʻe e pili ana i ka porosity, Pore pili loa ke ʻano a me ka nui o ka pore.
ʻO nā mea me ka hoʻoheheʻe wela maikaʻi e komo koke i ka wela a hoʻopau koke i ka wela. Inā makemake kekahi mau ʻōnaehana i ka nui o ka wela a i ʻole ka wela i ka wā e hoʻohana ai, koho ʻia nā mea me ka conductivity thermal maikaʻi. E like me ke kūlana conductivity thermal o nā metala maʻemaʻe, kālā, keleawe, aluminika, tungsten, magnesium a me nā mea ʻē aʻe, ʻoiai ʻoi aku ka maikaʻi o ka conductivity thermal o nā alloys. Hiki ke ʻike ʻia ka maikaʻi o ka conductivity thermal o ke keleawe wela ma waena o nā metala ʻoihana.

No laila, no ke aha i hana nui ʻia ai nā mea wela i ka alumini ma mua o ke keleawe?
He ʻoiaʻiʻo nō hoʻi e hana maikaʻi loa ke keleawe i ka wela no ka mea he ʻoi aku ka kiʻekiʻe o ka wela ma mua o ka alumini. Akā ʻo ka hiki ke hoʻoheheʻe wela o ka radiator ʻaʻole i hilinaʻi wale i ka conductivity thermal o ka mea, akā ma ka wahi hoʻoheheʻe wela, ke ʻano o ka radiator, a me nā kūlana kahe o ka ea.
No ka li'ili'i o ka wela wela o ke keleawe, pono e emi ka wela o ke keleawe, pi'i wikiwiki kona wela, a ma'alahi ka ho'opau 'ana i ka wela. Eia nō naʻe, ʻo ka nui o ke keleawe he 3.3 mau manawa o ka alumini. ʻO ka radiator kahi huahana o ka nui a ʻaʻole hiki ke hoʻonui mau ʻia. A laila ʻoi aku ke kaumaha o ke keleawe no ka leo like.
Ma lalo o nā kumu he nui, ʻoi aku ka nui o ke kumukūʻai o nā radiator keleawe ma mua o 400% ʻoi aku ka maikaʻi ma mua o nā radiators alumini, akā ma ke ʻano o ke kumukūʻai, ʻaʻole hiki i ka mākeke ke ʻae i nā radiator keleawe he 4 mau manawa ke kumu kūʻai.
No laila, aia kekahi mea i hiki ke loaʻa ka thermal conductivity o ke keleawe, akā ua like ka nui a me ke kaumaha me ka alumini?
He mea hou paha ke keleawe e pono ai ke nānā aku, he nui nā pores i hoʻopili ʻia a hoʻokaʻawale ʻia i loko o ka matrix keleawe. Foamed keleawe i maikai uila conductivity a me ka ductility, a he haʻahaʻa hoʻomākaukau kumu kūʻai a me ka maikai uila conductivity.