Chinese swords, throughout different periods of history, have been made from a variety of materials. The choice of materials depended on the available resources, technological advancements, and cultural preferences of the time. Here are some materials commonly used in the construction of Chinese swords:

1. Bronze: During ancient times, bronze was a common material used for Chinese swords. Bronze swords were cast using molds and were known for their strength and durability. These swords played a significant role in Chinese warfare during the Bronze Age.
2. Iron: As ironworking techniques advanced, iron became the primary material for Chinese swords. Iron swords were forged using traditional blacksmithing methods, such as heating, hammering, and quenching. Iron swords were known for their hardness, resilience, and sharpness.
3. Steel: Steel swords emerged during the Warring States period (475-221 BCE) in China. Steel swords were made by combining iron with carbon through a process called carburization. This produced blades with improved hardness, sharpness, and edge retention. Chinese steel swords were highly regarded for their quality and became a defining characteristic of Chinese martial arts and swordsmanship.
4. Pattern-Welded Steel: Pattern-welding was a technique employed in the making of some Chinese swords. This involved layering and forge-welding multiple layers of steel with different carbon content. The result was a blade with unique patterns and improved strength, flexibility, and sharpness.
5. Modern Materials: In contemporary times, modern steel alloys are often used in the construction of Chinese swords. These alloys offer a combination of strength, durability, and flexibility that meets the requirements of martial arts practice, historical reenactments, and collectors' preferences.

It's worth noting that the specific materials and techniques used in the construction of Chinese swords varied across different periods and regions in China. The craftsmanship and artistry of Chinese swordsmiths contributed to the development of distinctive sword styles and techniques throughout Chinese history.