1.比硬度，一块是铝一块是钛合金，只要二块材料相互划画。划伤的一块是铝。因为钛比铝硬度高。
1. The ratio of hardness, an aluminum one is titanium, as long as the two materials with each stroke painting. Scratched one is aluminum. Because titanium hardness than aluminum.
2.比耐酸，铝遇酸马上起化学反应，钛耐酸性很好。
2. The ratio of acid, aluminum case of acid from the chemical reaction immediately, good acid resistance of titanium.
3.比强度，用手钳、剪刀破坏铝很省力，钛很费力。
3. The specific strength, hand pliers, scissors very effort damage aluminum, titanium, very laborious.
4.比颜色，在一张白纸上划几下铝马上留下黑色划痕，钛看不见划痕。
4. The ratio of color on a piece of paper draw a few scratches on the aluminum immediately left black, titanium invisible scratches.