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.

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