What’re Relationships between Wear Resistance & Impact Resistance of CFRTPs?
Trade-off Relationship
In many cases, there is a trade-off relationship between the wear resistance and impact resistance of materials, where an increase in one property often leads to a decrease in the other.
Influence of Microstructure
When we aim to improve the wear resistance of materials, we usually take measures to change their microstructure. For example, in plastic materials, rigid wear-resistant particles (such as ceramic particles, glass fibers, etc.) are added as fillers. These fillers can increase the hardness of the material surface, making it less likely to be worn away when in contact with other objects, thus enhancing the wear resistance. However, from the perspective of impact resistance, these rigid particles will disrupt the originally continuous and relatively flexible molecular chain structure of the material. When subjected to external impact forces, the molecular chains will find it difficult to move freely and deform coordinately to disperse and buffer the impact energy. As a result, stress concentration is likely to occur in the material, leading to a decline in its impact resistance.
Similarly, for metal materials, surface hardening treatments (such as carburizing, nitriding and other processes) are used to enhance the wear resistance. This will form a hardened layer with relatively high hardness on the material surface. However, this hardened layer is relatively brittle and lacks sufficient toughness to absorb impact energy when subjected to large impact forces, thus causing the overall impact resistance of the material to deteriorate.
Association with Chemical Composition and Processing Technology
In terms of chemical composition, in order to improve the wear resistance, specific alloying elements are added (for example, adding chromium, molybdenum and other elements to steel to form wear-resistant alloy steel), or wear-resistant coating materials are used. These additives or coatings may change the overall toughness of the material and consequently affect its impact resistance. In terms of processing technology, for instance, increasing the crystallinity of materials to enhance wear resistance (which is common in some polymer materials) often means that the flexibility of the material is reduced. As a result, the material is more prone to fracture when impacted, and its impact resistance is also decreased accordingly.
Synergistic Relationship
Nevertheless, under certain material systems and conditions, the wear resistance and impact resistance can be promoted synergistically and improved simultaneously.
Composite Design Concept
Through reasonable composite design, for example, in the preparation of fiber-reinforced composite materials, suitable fibers (such as carbon fibers, aramid fibers, etc.) are combined with matrix materials (such as epoxy resin, polyimide and other matrices). The fibers can bear a part of the external force and help absorb and disperse energy when impacted, thereby enhancing the impact resistance of the material. Meanwhile, the fibers can also play a role in strengthening the structure inside the material, making the material surface more wear-resistant and reducing material loss caused by friction.
Optimization of Microstructure and Interface Control
Optimizing the microstructure of materials and controlling the interfaces between different phases also contribute to the simultaneous improvement of both properties. For example, in some metal matrix composite materials, through special preparation processes, a good interface bond is formed between the reinforcing phase (such as hard ceramic particles) and the metal matrix. When subjected to wear, the hard particles can effectively resist friction and improve the wear resistance. When impacted, the interface can effectively transfer stress and work together with the matrix and the reinforcing phase to disperse the impact energy, thus also improving the impact resistance.
Relatively Independent Relationship
In some application scenarios of materials, the wear resistance and impact resistance may also show a relatively independent relationship and do not interfere with each other.
Determined by Specific Usage Environments
For example, in applications where only static pressure or extremely low impact loads are endured, but continuous and slight wear mainly occurs (such as some mechanical seal parts with low-speed operation), the wear resistance of the material becomes the primary consideration factor, and the impact resistance has little impact on its actual application effect. Conversely, in some scenarios where impacts are only occasionally received and there is basically no wear (such as anti-seismic buffer parts in some building structures, where friction rarely occurs in normal times), the impact resistance is the key indicator, and the wear resistance is not the focus of attention.
Post time: Jan-09-2025