MATERIAL COMPARISON
Different material routes. A specific grade still matters.
TZM and lanthana-doped molybdenum are not two names for the same product. Compare the required grade and delivered condition before considering a substitution.
Comparison table
On a narrow screen, scroll the table sideways. Keyboard: focus the table and use the arrow keys.
| Criterion | TZM | Lanthanated molybdenum (MoLa) |
|---|---|---|
| Material route | Ti-Zr-Mo alloy. | Molybdenum stabilized with lanthanum oxide; specify the actual manufacturer grade. |
| Named grade examples | TZM is not a synonym for ML, MLR or MLS. | Plansee, lanthanum oxide content by mass: ML 0.3 %; MLR 0.7 %; MLS 0.7 %. |
| State identified in the reference | The TZM description does not establish the condition of a particular offered blank. | Plansee distinguishes recrystallized MLR from stress-relief-annealed MLS. |
| Semifinished product to compare | Request data for the actual sheet, rod or machined blank and section size. | Retain the specific grade and processing state for the same form and section size. |
Scope of the comparison
The percentages above are manufacturer-specific mass fractions of lanthanum oxide, not elemental lanthanum and not a specification for every product sold as MoLa. The reference does not supply a matched quantitative TZM/MoLa performance test.
Selection conditions
- Where a drawing already specifies TZM, a lanthanated grade is a proposed material change, not a renaming.
- For a selected MoLa product, decide whether the required semifinished form and delivered state match the actual offer; do not treat MLR and MLS as identical.
- For high-temperature duty, compare product-specific creep or mechanical data at the same temperature, atmosphere, load and exposure duration. The material names alone cannot identify a universal winner.
Sources for this table
Plansee: TZM, ML, MLR and MLS descriptions (English)References reviewed on 14 September 2026. Manufacturer references identify their own materials, not an MNK stock item or a supplier partnership.
What distinguishes these materials?
Plansee distinguishes Ti-Zr-Mo alloy TZM from lanthanum-oxide-stabilized ML grades; it also distinguishes recrystallized MLR from stress-relief-annealed MLS.
Plansee material descriptions (English)
Name the exact grade
Do not reduce a specified manufacturer grade to the generic label MoLa. Keep the grade reference attached to each offer.
Keep the condition visible
Record the offered condition beside the material name. A comparison loses meaning if one offer describes a finished part and the other an unspecified blank.
Compare the relevant requirement
Identify what the component must do in your process. Do not replace that requirement with a broad claim that one family is always better at high temperature.
A focused comparison for purchasing
- Start with the material designation on the drawing; list any proposed alternative separately.
- Compare the same product form, dimensions and quantity.
- Ask the supplier to relate the proposed grade and condition to the stated operating context.
- Have the person responsible for the design approve a material change before ordering.
This guide does not rank all TZM and MoLa products or assign a universal service temperature. Product-specific evidence and the project specification take priority.
Continue with the material pages
Source reviewed: 14 September 2026. Original procurement guidance by MNK-G.S.A.