Trojan Metallography

07/08/2026

🔎 Metallographic Sample Preparation for Copper Busbar Plating

High‑power conductive copper busbars and integrated shunt resistors commonly adopt a dual‑layer electroplating structure: 1.5‑4μm nickel underlayer + 3‑8μm tin top layer, balancing corrosion resistance and electrical assembly requirements.

Acting as a barrier layer, the dense nickel underlayer blocks outward diffusion and oxidation of copper substrate ions. It improves plating adhesion, enhances wear‑resistant and high‑temperature‑resistant performance, and mitigates fretting corrosion under vibration. This makes it ideal for demanding applications such as energy‑storage systems, DC charging piles and vehicle‑mounted electronic controls.

The outer tin coating delivers stable low contact resistance and excellent solderability. It deforms plastically under bolt compression, ensuring long‑term low‑thermal‑resistance performance at connection points.

Single tin plating suffers from Cu‑Sn interdiffusion, tarnishing and discoloration. Nickel‑only plating shows poor solderability. The combined nickel‑tin plating leverages strengths of both layers while avoiding their drawbacks. It is widely used in energy‑storage shunts, PV inverter busbars and high‑power new‑energy electrical connectors.

Key challenge for metallographic preparation of Ni‑Sn double‑layer coated busbars & shunts: handling this alternating soft‑hard thin‑layer structure.

Precise control over three critical steps is essential:

✅ Cutting: avoid thermal damage

✅ Mounting: prevent compression‑induced deformation

✅ Grinding & polishing: eliminate delamination and plastic flow

Standardized operation minimizes preparation artifacts, faithfully restores real microstructure and coating thickness, and delivers reliable metallographic data for coating‑thickness verification and process quality control.

04/08/2026

👍 At TROJAN, we do more than manufacture metallographic equipment and lab consumables — we embed rigorous quality control into every step of production.

All our grinding papers, cutting fluids, mounting compounds and other consumables undergo full performance testing in our in-house metallographic laboratory. No product leaves our factory until it passes all internal quality benchmarks. Consistent, reliable sample preparation results start with strict factory-side validation.

Trust TROJAN for stable, repeatable metallography solutions.

03/08/2026

🔎 Metallography Specimen Preparation for Mo-W Alloys

Mo-W alloys combine the superior properties of two refractory metals, featuring ultra-high melting points and excellent dimensional stability at elevated temperatures, widely adopted for high-temperature structural applications. Different from most hard alloys, Mo-W alloys are relatively softer with better ductility — a characteristic that creates challenges for metallographic sample preparation.

When processed on a countertop grinding & polishing system with co-rotating platens, continuous directional mechanical compression and cutting easily induce invisible plastic deformation layers on the sample surface. Such subsurface damage cannot be identified visually, yet it distorts the original crystal structure. It leads to misinterpretation of SEM images, unreliable EBSD orientation data and other errors during material characterization.

To solve this issue, we implement vibratory polishing as the final step of the workflow. Vibratory polishing delivers random, low-stress gentle micro-friction without directional aggressive cutting. It removes surface damage and residual stress accumulated during grinding and preliminary polishing, eliminates preparation-induced artifacts, and restores the true intrinsic microstructure of materials. This approach consistently yields high-quality specimens for high-precision characterization.

Preparation Parameters

1️⃣ Grinding: P400-P2500 grit | 15N | 50/150 rpm

2️⃣ Rough Polishing: SC cloth + 3μm polycrystalline diamond suspension | 15N | 50/150 rpm

3️⃣ Final Polishing: ZN cloth + 0.05μm alumina suspension | 18N | 50/150 rpm

4️⃣ Vibratory Polishing: ET cloth + 0.05μm alumina suspension | 100 mins

Metallographic micrograph results are shared below for your reference.

31/07/2026

🔎 Metallographic Sample Preparation Case: Alumina Ceramics

Alumina ceramics possess outstanding properties including high hardness, superior wear resistance, corrosion resistance and excellent insulation. As widely used structural and functional ceramics, they are applied in electronic insulation parts, precision wear-resistant components, high-temperature shielding, aerospace and metallurgy. Their microstructure directly governs the service performance and lifespan of finished products.

Metallographic examination allows clear observation of grain size, grain boundary morphology, pore distribution, microcracks and impurity defects to accurately assess sintering quality and microstructure homogeneity. Metallographic data helps optimize sintering parameters and prevent product failures such as cracking, abrasion and insulation breakdown. It is an essential technical foundation for mass production quality control, performance improvement and failure analysis of alumina ceramics.

Alumina ceramics feature high hardness and brittleness, making conventional sandpaper ineffective for grinding. Resin-bonded diamond grinding discs are adopted for coarse grinding, followed by fine grinding with a POH disc and 9 μm diamond suspension. Resin grinding discs provide cushioning during processing, avoiding severe longitudinal cracks and enabling efficient preparation of alumina ceramic specimens.

We share the metallographic preparation procedure for sintered alumina samples below for your reference:

1️⃣ Coarse grinding & planarization: P400DiaRe resin diamond grinding disc

2️⃣ Fine grinding: POH disc + 9 μm PD-WT suspension

3️⃣ Rough polishing: GF-JP disc + 3 μm PD-WT suspension

4️⃣ Final polishing: ZN disc + SO-T401 suspension

29/07/2026

🔎 Sample Preparation for Han Dynasty Bronze Mirrors

The Han Dynasty marked the golden age of ancient Chinese bronze mirror craftsmanship. Mirrors were predominantly cast from a ternary alloy of lead, tin and copper with a classic ratio roughly 14:5:1. Lead improves the fluidity of molten alloy, enabling sharply defined decorative patterns, stable forming and mass production — a remarkable achievement of Han metallurgical technology.

After thousands of years underground, these bronze mirrors develop porosity, segregation and corrosion layers. These unique microstructures create major challenges for metallographic sample preparation of cultural relics.

Key challenges of Han bronze mirror metallography: Uneven hardness across the specimen; lead phases prone to shedding. Grinding easily causes scratches and surface deformation. Loosely bonded corrosion layers tend to peel off during polishing, creating false features that distort observations of the original casting microstructure.

Truly has developed a complete workflow to solve these difficulties:

✅ Table-CUT200 automatic precision cutting minimizes thermal damage

✅ Sequential grinding with graded abrasive papers (paraffin can be applied as needed)

✅ ThetaVAC-2 vacuum impregnation fills irregular pores to achieve superior metallographic imaging

✅ Diamond polishing suspension followed by silica final polishing removes fine scratches and surface deformation

✅ Ultrasonic cleaning for porous areas

This workflow preserves intact original microstructures, accurately revealing casting techniques of Han bronze mirrors and delivering reliable data for cultural heritage research.

Recommended Preparation Parameters

1️⃣ Grinding: MET-SP P800–2500

2️⃣ Rough polishing: SC + 0.05μm Super

3️⃣ Final polishing: ZN + 0.05μm 439

27/07/2026

🔎 Metallographic Sample Preparation for Nylon & PET Fiber Cross-Sections

The cross-sectional morphology of nylon and PET fibers holds critical clues to material performance. Metallographic analysis reveals distinct fiber cross-section geometries—standard circular, custom cross-shaped, hollow or trilobal profiles. These microstructures directly govern fiber luster, hand feel, moisture absorption and mechanical strength.

For instance, hollow cross-sections deliver lightweight warmth, while profiled shapes improve moisture wicking. Engineers utilize metallographic observation to rapidly identify fiber types, evaluate spinning process consistency, and detect defects such as air bubbles, irregular profiles and voids.

Whether for process optimization, quality improvement or failure investigation, cross-section metallographic analysis acts as a "microscope lens" linking microstructures to macroscopic properties, supporting material innovation.

Preparation Procedure for Nylon & PET Fiber Specimens

*️⃣ Mounting: TJ2226 resin

*️⃣ Grinding 1: P800 MET-SP abrasive disc

*️⃣ Grinding 2: P2000 MET-SP abrasive disc

*️⃣ Polishing 1: SC-JP 1 μm PD-WT polishing cloth

*️⃣ Polishing 2: ET-JP 0.05 μm AO-W polishing cloth

22/07/2026

🔎 Metallographic Sample Preparation for Titanium Alloys

Titanium alloys feature high strength, low density, outstanding corrosion resistance and thermal stability, making them vital lightweight materials for advanced manufacturing. Balancing superior mechanical properties and reliability, they perform well under harsh service conditions. They are widely adopted in aerospace structural components, premium medical devices, marine equipment, chemical machinery and other sectors, serving as a key material driving high-end industrial development.

However, metallographic preparation of titanium alloys is far more challenging than conventional steels. Preparation artifacts frequently interfere with accurate microstructure observation. Three major challenges stand out:

✅ High ductility leads to deformed layers and mechanical twins during cutting and grinding, obscuring genuine microstructures.

✅ Poor thermal conductivity traps heat during grinding/polishing, triggering surface microstructural alterations.

✅ A hard native oxide film easily forms on the surface, leaving fine scratches after polishing and poor contrast post-etching.

Our optimized workflow addresses these pain points:

• Use Trully custom S-series cutting discs to minimize mechanical and thermal damage

• Cold mounting is recommended to avoid hydrogen fluctuation caused by hot mounting

• MET-P abrasive papers for rough grinding, paired with POS plates for gentle fine grinding

• Final chemo-mechanical polishing with ZN cloth + SO-A439 suspension to fully remove deformed layers and oxide films, revealing authentic titanium alloy microstructures.

Standard preparation sequence:

1️⃣ Rough Grinding: MET-SP P400

2️⃣ Fine Grinding: POS Plate + 9μm PD-WT Polycrystalline Diamond Suspension

3️⃣ Rough Polishing: SC Cloth + 3μm PD-WT Polycrystalline Diamond Suspension

4️⃣ Final Polishing: ZN Cloth + SO-A439 Silica Suspension

22/07/2026

20/07/2026

🔎 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 pe*******on, 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