What types of applications would metals not be suitable materials?

Metals are generally unsuitable for applications requiring high corrosion resistance, such as in marine environments or chemical processing, where polymers or specialized coatings might be more effective. Additionally, in applications that demand lightweight materials, such as in aerospace or certain consumer electronics, composites or advanced plastics are often preferred. Finally, in situations requiring Excellent electrical insulation, such as in electrical wiring insulation, non-metal materials like rubber or ceramics are more appropriate.