Material Analysis: Matched Pair of Antique Philippine Blades with Crystalline Matrix

[Oiluj13]

Hello everyone,
This is my first post on the forum—thanks for adding me! I am seeking your collective expertise to help identify a highly unique group of antique Philippine blades
My primary goal is to bring the unique composition and internal metal matrix of the matching twin pair into focus for the group.
Unlike standard acid etching or rust pitting, the steel on these two companion blades displays a dense, smooth, high-contrast micro-crystalline structure that is entirely flush with the surface plane. The pattern becomes intensely reactive and shows distinct optical chatoyancy under glancing, sideways light.
To help with the analysis, I have included a close-up image contrasting all three types of steel in my collection side-by-side: the granular crystalline matrix of the twin set, a heavily layered pattern-welded blade, and a standard carbon steel edge. I would deeply appreciate your insights on:
The Steel Matrix: What specific type of crucible or specialized lamination method is responsible for this smooth, granular, micro-carbide crystal segregation?

Thank you very much for your time, analysis, and guidance!

[Lee]

The 'patina' and rough finish could be obscuring something, but these appear to be tool grade and made with a 'modern' steel. I have a few Philippine pieces from the 1980s that they remind me of. Serviceable and fit for their intended function.

[Pendita65]

HI,

the first photo shows a Keris from Madura Indonesia it is laying diagonal over the other daggers. And the Ukiran (hilt) is faced the wrong way it should turned 180 degrees.

Regards, Martin

[Oiluj13]

Hi guys just wanted to show a close up of my blade. Has anyone else seen a close up of leaf steel like this?

[A. G. Maisey]

I believe that the perceived crystalline pattern that you can see is very likely the result of "cold forging", in reality the material is not cold when it is hammered, it has gone into the black heat range, and a bladesmith will sometimes continue his hammering into this heat range because it is believed --- & is possibly true --- that this "cold forging" will result in a higher degree of compacted material and a harder blade.

From experience I can say that if a mild steel, say below .5% carbon, has been used to make the blade, this "cold hammering" does work, because we do not draw a low carbon steel, we only quench at critical heat --- ie, where the material loses its magnetic properties.

If cold forging were to be used with a high carbon steel, this would really be counter intuitive & counter productive, because the correct heat treat cannot be improved upon.

[Ian]

Hello Oiluj13,

Welcome to the Forum and thank you for posing these questions.I would suggest that the two Luzon knives (which you call a "twin set") have been left to the elements and insect predation in the past. The damage to the horn hilts is usually caused by horn beetles. Both blades also show heavy oxidation, which makes any assessment of the underlying blade very difficult. While I can understand a desire to retain the age patina of a piece, the only thorough way to assess crystalline structure of the steel is to remove any oxidation and then etch the blade. This means polishing the blade back to white and etching it with an acidic solution.

It is hard to judge the age of the "twin set" but I think they are both 20th C and perhaps post-WWII. As such, they are likely made from monosteel and leaf springs are a common stock source.

The smaller dagger may be an Ilokano knife from northern or central Luzon. Again, it is too oxidized to assess IMHO. I would suggest that you also polish and etch that blade if you want to see its metallurgical features.

As noted, the obviously laminated blade is an Indonesian keris from Java.

Your three Filipino knives from Luzon need some care if you plan to keep them. Although some of the oxidation appears old and not particularly active, I would nevertheless suggest removing the rust (either mechanically or with an acid treatment) and oil the blades.

Regards, Ian.

[Oiluj13]

Hi Ian thank you for your suggestion and your Insite. The twins have been stabilized and treated with reannounce wax. What looks like pitting on those two blades is actually counterintuitive as they are almost completely smooth. if you run your finger across the flat of the blade it feels almost completely smooth i can however feel tiny bumps with my fingernail. I took your advice and conducted a window coffee etch and i will post side by side comparison on the bolo knife that i believe is leaf spring or scrap metal forged and the chopper of the twins i will attach copies of each as well as side by side pics for your consideration. Also, the handles of both are carved not damaged i will post pics of the handles as well as the damaged beetle eaten handle of the smaller knife side by side. I forgot to post pics of the sheaths that might help pin down when they were made. do you know anything about cyphers or marks on blades. both of the twins have the same type of mark like an m or a zig zag the chopper on the blade and the straight blade has it carved into both sides of the handle at the same spot Thanks again for your info.