Good luck with the firewood saw. Look up the material properties of titanium alloys if you get a chance. It is strong, light, and smears like most aluminum alloys and and some stainless alloys. Its not about heat resistance, or strength, it is resistance to galling that matters in this application. The surface will smear under the wrist pin bearing.
To be fair maybe you'll get away with it. I'm no engineer, just a hillbilly that reads. If so please let me know. Sometimes you have to be the guy peeing in the wind during the forest fire. It might be the smart choice that day.