It is all comparative but Titanium is still metal and therefore heavier than materials like G-10 and carbon fiber. But out of metals that are strong enough to be used in knifemaking I believe only aluminium is lighter than Ti.
This is why a combination of Ti and G-10 is viewed by many (myself included) as the ultimate solution if you are into framelocks. G-10 is also grippier and 'warmer' than Ti.
From Wikipedia: The two most useful properties of the metal form are corrosion resistance and the highest strength-to-weight ratio of any metal.[5] In its unalloyed condition, titanium is as strong as some steels, but 45% lighter.[6]
Due to their high tensile strength to density ratio,[7] high corrosion resistance,[3] fatigue resistance, high crack resistance,[51] and ability to withstand moderately high temperatures without creeping, titanium alloys are used in aircraft, armor plating, naval ships, spacecraft, and missiles.[3][4] For these applications titanium alloyed with aluminium, vanadium, and other elements is used for a variety of components including critical structural parts, fire walls, landing gear, exhaust ducts (helicopters), and hydraulic systems. In fact, about two thirds of all titanium metal produced is used in aircraft engines and frames.[52] The SR-71 "Blackbird" was one of the first aircraft to make extensive use of titanium within its structure, paving the way for its use in modern military and commercial aircraft. An estimated 59 metric tons (130,000 pounds) are used in the Boeing 777, 45 in the Boeing 747, 18 in the Boeing 737, 32 in the Airbus A340, 18 in the Airbus A330, and 12 in the Airbus A320. The Airbus A380 may use 146 metric tons, including about 26 tons in the engines.[53] In engine applications, titanium is used for rotors, compressor blades, hydraulic system components, and nacelles. The titanium 6AL-4V alloy accounts for almost 50% of all alloys used in aircraft applications.[54]
Due to its high corrosion resistance to sea water, titanium is used to make propeller shafts and rigging and in the heat exchangers of desalination plants;[3] in heater-chillers for salt water aquariums, fishing line and leader, and for divers' knives. Titanium is used to manufacture the housings and other components of ocean-deployed surveillance and monitoring devices for scientific and military use. The former Soviet Union developed techniques for making submarines largely out of titanium, which became both the fastest and deepest diving submarines of their time.[55]
