History of engineering & technology Technology: general issues anticorrosion steel area rate atmospheric plasma sources biomimetic model bionic crack blocked unit brake pads cast irons cement-based material chemical analysis composition corrosion susceptibility defocusing dielectric barrier discharge ductile iron energy excess hardness heat diffusion high entropy alloy laser beam mode laser bionic unit laser cladding laser melting laser polishing laser powder bed fusion laser remelting laser scabbling laser treatment mechanical properties