Matthew Gregory
Chief Executive in charge of Entertainment
- Joined
- Jan 12, 2005
- Messages
- 6,399
Sam 'mecha' Taylor of Mad Science Forge and I have been talking for quite a while now, and during one of our chats it was suggested that he forge me up a billet of his Beta Titanium so I could make one of my kwaiken out of it. I have almost no experience with Titanium, much less his alloy, so I'll let him do the explaining. He says:
"There are a dozen or so established titanium alloys commonly produced, with the vast majority being an iteration of 6al4v or commercially pure grades. Some titanium alloys are produced in one-off batches for special aerospace, outer space, military or scientific purposes. This alloy is a unique batch made for Boeing sometime in the 1990s, original purpose unknown. It is unique among ti alloys because it only has one main alloying element, niobium, along with a tiny amount of iron:
89.5Ti 10Nb 0.5Fe
A few alloys of titanium, including this one, are blended with a large amount of 'beta stabilizer' elements, which among other things increases the alloy's strengths and allows for creative heat-treatment. This 'beta metastable' (can exhibit two or more stable crystalline structures) TiNb alloy is very beautiful and clean, and produces a rigid and strong, tough, lightweight large blade that is highly resistant to crack propagation, breakage, or gross deformation. I think of it as the titanium alloy equivalent of a very pure high carbon steel, while other ti alloys I think of as tool steels which include other alloying elements for their various effects.
The normal 'alpha phase' crystal structure of titanium is hexagonal (HCP), and the 'beta phase' at elevated temperatures is cubic (BCC). With enough beta stabilizer elements, ti can be quenched and hold a stable cubic crystalline phase (beta titanium alloy). This beta phase is used as a heat-treatment vehicle to achieve the final product, a very strong and relatively hard HCP form of titanium that resembles martensite, called 'alpha prime.' These blades are forged and heat-treated by hand and eye, so every one is different. It's always exciting and illuminating to see what a skilled blademaker like M.Gregory will create with a forged billet of this rare ti alloy!"
-Mecha
I did everything to make it look like a knife, while Sam did all the processing and heat treating. As it's his material, I wanted to leave as much of the processing to him, and I also wanted to make sure it was evident at first glance that it had been forged. Most of the blades that I've seen from him, and anyone else that have used his Titanium, have all had fine satin finishes, and I wanted to offer a contrast to that, so I elected to use a machine finish for the primary bevel. The spine, however, has been rounded, and brought to a high polish. Average thickness of the piece is .200" thick, with a 6-1/2" blade, and a 5" handle. I've added a slightly soft material under the bright red rayskin to bolster the handle a bit for a hand-filling feel, while not adding too much bulk or weight. A slight 'coffin' shape to the butt aids in snap-cutting, and feels secure in hand. The wrap is carbon fiber lace soaked in aerospace resin.
Titanium is almost disconcertingly light. Despite the length of this blade, the knife itself tips the scale are a ridiculously light 6 ounces! Even with the carbon fiber wrapped aluminum sheath, it's just over 9 ounces TOTAL.
The sheath is ultrasuede lined, for smooth and quiet retention, and features a small black G10 kurigata as well as some resin-soaked carbon fiber lace.
Thanks for looking gang, hope you like it!
"There are a dozen or so established titanium alloys commonly produced, with the vast majority being an iteration of 6al4v or commercially pure grades. Some titanium alloys are produced in one-off batches for special aerospace, outer space, military or scientific purposes. This alloy is a unique batch made for Boeing sometime in the 1990s, original purpose unknown. It is unique among ti alloys because it only has one main alloying element, niobium, along with a tiny amount of iron:
89.5Ti 10Nb 0.5Fe
A few alloys of titanium, including this one, are blended with a large amount of 'beta stabilizer' elements, which among other things increases the alloy's strengths and allows for creative heat-treatment. This 'beta metastable' (can exhibit two or more stable crystalline structures) TiNb alloy is very beautiful and clean, and produces a rigid and strong, tough, lightweight large blade that is highly resistant to crack propagation, breakage, or gross deformation. I think of it as the titanium alloy equivalent of a very pure high carbon steel, while other ti alloys I think of as tool steels which include other alloying elements for their various effects.
The normal 'alpha phase' crystal structure of titanium is hexagonal (HCP), and the 'beta phase' at elevated temperatures is cubic (BCC). With enough beta stabilizer elements, ti can be quenched and hold a stable cubic crystalline phase (beta titanium alloy). This beta phase is used as a heat-treatment vehicle to achieve the final product, a very strong and relatively hard HCP form of titanium that resembles martensite, called 'alpha prime.' These blades are forged and heat-treated by hand and eye, so every one is different. It's always exciting and illuminating to see what a skilled blademaker like M.Gregory will create with a forged billet of this rare ti alloy!"
-Mecha
I did everything to make it look like a knife, while Sam did all the processing and heat treating. As it's his material, I wanted to leave as much of the processing to him, and I also wanted to make sure it was evident at first glance that it had been forged. Most of the blades that I've seen from him, and anyone else that have used his Titanium, have all had fine satin finishes, and I wanted to offer a contrast to that, so I elected to use a machine finish for the primary bevel. The spine, however, has been rounded, and brought to a high polish. Average thickness of the piece is .200" thick, with a 6-1/2" blade, and a 5" handle. I've added a slightly soft material under the bright red rayskin to bolster the handle a bit for a hand-filling feel, while not adding too much bulk or weight. A slight 'coffin' shape to the butt aids in snap-cutting, and feels secure in hand. The wrap is carbon fiber lace soaked in aerospace resin.
Titanium is almost disconcertingly light. Despite the length of this blade, the knife itself tips the scale are a ridiculously light 6 ounces! Even with the carbon fiber wrapped aluminum sheath, it's just over 9 ounces TOTAL.
The sheath is ultrasuede lined, for smooth and quiet retention, and features a small black G10 kurigata as well as some resin-soaked carbon fiber lace.
Thanks for looking gang, hope you like it!
Last edited:
