Artists often harness the natural and artificial processes of time and decay to infuse metal sculptures with depth, history, and emotional resonance. One common technique is oxidation, where metals like iron or steel are deliberately exposed to moisture, creating rust—a visual metaphor for aging and impermanence. Others apply chemical patinas to copper or bronze, accelerating the formation of vibrant greens, blues, or blacks that evoke centuries of weathering in mere weeks.

Some sculptors incorporate found objects—rusted machinery, weathered tools, or corroded fragments—to embed literal traces of time into their work. Kinetic sculptures take this further, using movement to simulate erosion or disintegration over prolonged display. Contemporary artists like Anselm Kiefer even bury metal pieces to let earth and microbes "sculpt" them organically.

Beyond aesthetics, these methods invite viewers to contemplate mortality, environmental change, and the beauty of transience—proving that in skilled hands, decay becomes not destruction, but collaboration with time itself.