Metallographic Prep Recipe for Laser-Welded Aluminum Busbars
Aluminum busbars are core conductive components for new energy battery modules, power electronics & energy storage systems. The integrity of laser welds directly determines current-carrying performance and long-term operational reliability.
Laser welding has become the mainstream joining process for Al busbars, featuring narrow heat-affected zones, high speed, and non-contact processing—efficiently overcoming aluminum’s high laser reflectivity and rapid oxidation issues. But surface appearance cannot reflect true weld quality.
Metallographic cross-section analysis is mandatory to quantify weld penetration, bead width, porosity, HAZ microstructure, and detect hidden defects: microcracks, incomplete fusion, overheating. This micro-level inspection guides laser parameter optimization and acts as a rigid safety & lifespan benchmark. Moving from “just welded” to “reliably welded” relies fully on precise metallographic quality control to guarantee every joint withstands long-term current loads and service cycles.
Standard Specimen Preparation Workflow
1️⃣ Coarse Grinding 1: MET-SP P800
2️⃣ Coarse Grinding 2: MET-SP P1200
3️⃣ Coarse Grinding 3: MET-SP P2000
4️⃣ Coarse Grinding 4: MET-SP P2500
5️⃣ Primary Polishing: CS 3μm AO-W suspension
6️⃣ Intermediate Polishing: ET 1μm AO-W suspension
7️⃣ Final Mirror Polishing: ZN 0.05μm SO-A439 colloidal silica Etchant: Keller’s Reagent
Critical Notes
Coat sandpaper with wax or use continuous lubrication during all 4 grinding steps to avoid thermal damage to aluminum microstructure
Rinse samples thoroughly with clean water after every polishing stage before proceeding to the next step
