https://aluconice.com/%d9%88%d8%b1%d9%82-%da%a9%d8%a7%d9%85%d9%be%d9%88%d8%b2%db%8c%d8%aa-%d8%a7%d8%b1%d8%b2%d8%a7%d9%86/

heets are a type of material that is made by combining two or more different materials