Why hardness alone does not predict wear life

A hardness result is produced by a named test, indenter, load and preparation. Mohs, Vickers, Rockwell and Brinell do not express the same thing and their numbers are not interchangeable. Even within one method, the exact material grade, microstructure, specimen condition and reported uncertainty matter. A useful technical comparison therefore identifies the standard and test method instead of presenting an isolated number. The value can support screening, but it does not reproduce a chute, slurry elbow or impact point.

A hard contact surface can be valuable under supported sliding abrasion or particle erosion, but repeated impact introduces fracture, edge and support questions. Corrosion can weaken the steel shell or bond line while the ceramic face remains little worn. Vibration and thermal cycling can load joints and attachment. Before ranking materials, identify where particles strike, slide and accelerate, and distinguish normal operation from upset conditions. The relevant property set follows that diagnosis; it cannot be reduced to one hardness value.

A lining includes the ceramic format and thickness, substrate, backing, adhesive or mechanical retention, joints, transitions and edge details. An unsupported void, flexible shell, exposed cut or poorly prepared surface can control failure before the wear face is consumed. Geometry also determines whether a rigid tile can remain continuously supported. Review drawings, tolerances, access and installation procedure with the material data. A higher nominal hardness cannot compensate for a construction that permits movement or concentrates load at an edge.

Particle size and shape, solids concentration, velocity, drop height, angle, temperature, moisture, chemistry and start-stop cycles define the duty. A change in feed source or throughput can move the strike point or increase turbulence. A material that performs well in one asset is therefore not automatically transferable to another with a similar name. Record the actual operating range and the failure location, then compare only references that share the controlling mechanism and broadly comparable geometry and attachment.

Ask for the exact grade, composition range where relevant, physical-property test method, specimen condition and quality documentation. Separate measured values from typical values and from unverified claims. For operating references, record asset geometry, handled material, process range, installation details and inspection basis. A statement such as ‘lasts several times longer’ is not portable without its denominator and conditions. A defensible comparison explains both why the evidence is relevant and where its limits remain.

When comparable history is weak, use a representative trial area or a clearly mapped first installation. Record dimensions, photographs, lining layout, operating hours or throughput and any process changes. Agree where and how thickness, joint condition and attachment will be inspected. The objective is not to prove a preferred material; it is to learn which component controls performance under the real duty. Hardness remains one input in that record, while measured wear and failure mode determine the next decision.