Cheap yet ultrapure titanium might enable widespread use in industry (2024)

Original Article ↗ Hacker News Discussion ↗

New deoxygenation method & the yttrium problem

  • The Nature paper’s process removes oxygen from molten titanium using yttrium metal plus yttrium fluoride.
  • Resulting titanium can contain up to ~1% yttrium by mass; commenters note this contradicts “ultrapure” marketing.
  • Debate centers on whether 1% Y is acceptable:
    • Oxygen is extremely harmful to titanium’s ductility; trading O for Y may be a net win.
    • Yttrium is already used in some alloys and is likely benign for many structural/industrial uses but undesirable for implants or highly specialized alloys.
  • Economically, yttrium is expensive and supply‑constrained; 1% content could add notable cost and create geopolitical risk, leading some to label this potentially uneconomic without further process refinement.

Alternatives and follow‑on processing ideas

  • Commenters list other approaches: molten‑salt electrolysis (FFC Cambridge/OS), calciothermic routes, hydrogen plasma arc melting, calcium‑based deoxidation, magnesium hydride reduction, and solid‑state routes (e.g., Metalysis).
  • No clear consensus on which are most efficient or scalable; details are mostly at the “survey of ideas” level.
  • Ideas like separating yttrium by density from molten titanium or grinding off deoxygenated surface layers are raised but quickly run into practicality issues given titanium’s machining difficulty.

Titanium’s real bottleneck: manufacturability, not ore price

  • Multiple practitioners stress that raw material cost is only a fraction of titanium part cost.
  • Core problems:
    • Very low thermal conductivity → localized overheating during machining.
    • High reactivity when hot → ignition risk, especially shavings and in reactive atmospheres (e.g., wet chlorine pipelines).
    • Difficult casting (high melting point, inert atmospheres), poor ductility for forming, specialized tooling and copious coolant needed.
  • As a result, machining time, tool wear, safety measures, and process constraints dominate the economics.

Material behavior & comparison to other metals

  • Discussion explains “protective oxides”: Al, Ti, stainless steels form thin, adherent oxides that block further corrosion; iron rust is porous/flaky and accelerates corrosion instead.
  • Yttrium is framed as a “getter”: a less harmful impurity that binds oxygen, analogous to how steelmaking adds elements to capture undesirable impurities.

Impact on industrial and consumer use

  • Skeptical view: even if titanium sponge becomes cheap, widespread substitution for steel/aluminum is unlikely; it remains hard and dangerous to work, so everyday items won’t suddenly switch.
  • Nuanced counterpoint: cheaper titanium could expand some niches—3D‑printed aerospace parts, eyeglass frames, corrosion‑critical components, medical devices where Y contamination can be managed or avoided.
  • For things like phones and watches, several argue titanium is mostly marketing: weight savings are small, hardness is worse than stainless, and scratch resistance isn’t better.

Energy-cost and fusion tangent

  • One line of discussion wonders if cheaper energy (solar, future fusion) will naturally make titanium production cheap regardless of process.
  • Replies range from “fusion is always 20 years away” skepticism to cautious optimism about well‑funded private fusion efforts; no resolution, and relevance to near‑term titanium economics is left unclear.