What is the surface roughness of a material? How hard is my material?
Think about: What is the depth-scale of the roughness? What spatial resolution is required?
The Bruker Innova AFM (atomic force microscope) measures the smallest surface-height differences and is able to image atomic-scale roughness. AFM provides non-destructive characterization of surface roughness with a resolution of < 0.1 nm via contact or tapping mode over an area up to 250um x 250 um x 100 um. Spatial resolution > 2 nm.
- The Bruker Inova AFM provides atomic resolution roughness analysis with atomic resolution. Samples may be analyzed in air or in liquid. Users should bring their own tips. AFM scans have better resolution, but are more time-consuming than optical methods.
The Zygo white-light optical profilometer has ~ 1nm resolution and is specifically utilized for determination of surface topography and measurement of surface shape, surface finish, surface profile roughness (Ra), or in surface area roughness (Sa), surface texture, asperity and structural characterization.
- The Zygo profilometer provides a nondestructive, Interferometric method for area and height measurement with a depth resolution of < 1nm +/- < 0.1nm and a lateral resolution of 360 nm. Information can be acquired over a field of view: 0.03 to 14 mm. Also measures thin film thickness.
Optical measurements and models of surface roughness can be made with the Hirox Digital Light Microscope with minimal sample preparation and in a short amount of time. Roughness of > 20 nm can be determined.
- The Hirox Digital Microscope provides 2D and 3D surface images, as well as videos, from 1x - 5000x magnification, and can be used for measurements of surface cross-sectional roughness (Ra, Rz, Rzjis) and feature length, height, and volume. Good for measurements on steep flanks and very rough surfaces.
Scanning electron microscopy (SEM) provides sample surface imaging down to the nanoscale, from 6x to 500,000x magnification for roughness determination and measurement.
The Quanta 650 SEM allows imaging of conductive sample surfaces (ESEM or coated samples) to magnifications as large as 500,000x. The Quanta 650 can operate in high & low vacuum modes, as well as ESEM.
Think about: How hard is my material? At what point does it fracture?
- Rockwell Hardness Testing ( Wilson Model 4 ) is the most commonly used hardness tester and can be used with all metals, based on choice of scale. This indentation method of hardness testing is used for most parts, except thin materials. Forces are typically 3 kg - 150kg.
- Vickers Hardness Testing, also referred to as the microhardness test method, is an indentation method mostly used for small parts and thin sections. NMCF has a Bühler Micromet 5101 Vickers hardness tester with camera and set-up for Knoop testing for very thin materials. Forces are typically 10 - 1,000g.