GB/T 34498-2017 in English

National Standard of the People's Republic of China GB/T 34498—2017

Tungsten Cathode Materials for Laser Lamps

Standard Overview

This standard specifies the requirements, test methods, inspection rules, marking, packaging, transportation, storage, quality certificates and contract (or order form) contents for tungsten cathode materials for laser lamps. It is applicable to tungsten cathode materials for laser pump lamps and their applications in laser processing (cutting, welding, drilling, heat treatment, engraving), high-power lasers, laser beauty lamps and pulsed germicidal lamps.

Classification and brand

Specifications and dimensional tolerances

Product specifications and dimensional tolerances shall conform to the provisions of Table 2 (unit: mm):

Density requirements

The density of WT20, WC20, and WX cathode materials should be ≥18.2 g/cm³, the density of WT40 and WC40 cathode materials should be ≥17.9 g/cm³, and the density of WBa cathode matrix materials should provide the measured value.

Appearance quality and internal quality

• The end face should be a straight section, the surface should be uniform, without oxidation, grease, impurities, burrs, and obvious visible defects.
• There should be no looseness, inclusions, faults, cracks, and other defects that affect the performance. The porosity of the WBa material matrix is 15% to 30%.

Surface roughness

Surface roughness Ra ≤ 1.6 μm.

Straightness requirements

The product should be straight, and the straightness of each 100 mm long (or shorter) cathode material should not exceed 0.5 mm.

Test methods and inspection rules

Chemical composition determination

• WC20, WC40: Cerium oxide content is determined according to YS/T500.
• WT20, WT40: Oxide content is determined according to YS/T501.
• The method for barium salts and other rare earth oxides shall be determined by negotiation between the supply and demand parties.
• Impurity elements shall be determined according to GB/T 4324.

Density determination

Carry out in accordance with GB/T 3850.

Appearance and internal quality

• Appearance is visually inspected, and end defects are inspected with a magnifying glass.
• Internal defects of non-WBa materials are detected by eddy current flaw detector.
• Porosity of WBa materials is tested in accordance with GB/T 21650.1 or industrial CT.

Straightness determination

Use a smooth and flat surface to detect using the circular chord method.

Implementation suggestions

1. Suppliers should strictly follow the standards for production and inspection to ensure that product quality meets the requirements.
2. The purchaser should conduct sampling inspections in accordance with the standards during acceptance, especially key indicators such as chemical composition and density.
3. For non-routine testing items (such as electronic work function, performance, and grain size), they should be clearly stipulated in the contract based on actual needs.
4. It is recommended to establish a long-term quality monitoring mechanism to ensure supply chain stability and product consistency.