*3.1. ASTM G65-00 Metal–Mineral Abrasion Resistance Test*

The tests of abrasive wear resistance for the selected materials were carried out in accordance with ASTM G 65-00. Procedure A, which is the most demanding examination of abrasion resistance, was used for the tests. During the test, the sample was mounted in a special fixture in which it was clamped to a rubber wheel 228.6 mm in diameter. The test sample was pressed against the rubber wheel with a force of 130 N. Abrasive in the form of granular sand (gradation 250 μm) was delivered through the nozzle at the location of sample contact with the rubber wheel. The abrasive flow rate was 300–400 g/min. The wheel rotated in the direction corresponding to the abrasive flow, at a speed of 200 rpm through 6000 revolutions. The tested samples were 25 × 75 × thickness of the sample, mm, as shown in Figure 5. The mass loss was determined using an analytical balance precise to 0.0001 g (measurement accuracy up to 5 decimal places). To compare the results of abrasion resistance, the density of plates and abrasive layers was determined. As a measure of abrasion, the volume loss of the sample (mm3) was determined, and is shown in Equation (1), Table 7, and Figure 6.

$$Volume\,\,loss\,\,(\text{mm}^3) = mass\,\,loss\,\,(\text{g}) \,\,:\, density\,\,(\frac{\text{g}}{\text{cm}^3}) \times 1000\,\tag{1}$$

**Figure 5.** Abrasion tests samples following the abrasion test: (**a**) NANO; (**b**) ABRECOPLATE; (**c**) CDP; (**d**) ABRADUR 64; (**e**) WC; (**f**) HARDOX 400.

The tests have shown that the relative resistance to metal-to-metal abrasive wear of the nanocrystalline layer is 11 times higher when compared to the Hardox400 reference metal sheet.


CDP/7.1724

ABRADUR

 64/7.1544

WC/10.6808

2

1

2

1

2

1

2

1

2

 173.6714

 128.6154

 128.9438

 136.2893

 139.6675

 179.6026

 181.8750

 62.1029

 62.5591

\*

 173.5589

 128.4378

 128.7821

 136.0933

 139.4670

 179.3009

 181.5295

 61.0320

 61.4918

 1.0709

 1.0673

 400.

1.0691

 138.8705

 1.00

 0.1125

 0.1776

 0.1617

 0.1960

 0.2005

 0.3017

 0.3455

0.32360

 30.2974

 4.58

0.19825

 27.7102

 5.01

0.1697

 23.3881

 5.94

**Average Volume**

**Relative Abrasion**

**Resistance \***

**Loss (mm3)**

 12.6765

 15.3170

 9.07

 10.95

*Materials* **2018**, *11*, 1184

HARDOX 400/7.7115 Relative abrasion resistance compared to HARDOX

**Figure 6.** Comparison of the results of relative abrasive wear resistance of selected construction materials.
