Abrasion is the process of scuffing, scratching, wearing down, marring, or rubbing away. It can be intentionally imposed in a controlled process using an abrasive. Abrasion can be an undesirable effect of exposure to normal use or exposure to the elements.
Ancient artists, working in stone, used abrasion to create sculptures. The artist selected dense stones like carbonite and emery and rubbed them consistently against comparatively softer stones like limestone and granite. The artist used different sizes and shapes of abrasives, or turned them in various ways as they rubbed, to create effects on the softer stone's surface. Water was continuously poured over the surface to carry away particles. Abrasive technique in stone shaping was a long, tedious process that, with patience, resulted in eternal works of art in stone.
The Archard equation is a simple model used to describe sliding wear and is based on the theory of asperity contact.
The resistance of materials and structures to abrasion can be measured by a variety of test methods.These often use a specified abrasive or other controlled means of abrasion. Under the conditions of the test, the results can be reported or can be compared items subjected to similar tests.
Such standardized measurements can produce two quantities: abrasion rate and normalized abrasion rate (also called abrasion resistance index). The former is the amount of mass lost per 1000 cycles of abrasion. The latter is the ratio of former with the known abrasion rate for some specific reference material.
One type of instrument used to get the abrasion rate and normalized abrasion rate is the abrasion scrub tester, which is made up of a mechanical arm, liquid pump, and programmable electronics. The machine draws the mechanical arm with attached brush (or sandpaper, sponge, etc.) over the surface of the material that is being tested. The operator sets a pre-programmed number of passes for a repeatable and controlled result. The liquid pump can provide detergent or other liquids to the mechanical arm during testing to simulate washing and other normal uses.
The use of proper lubricants can help control abrasion in some instances. Some items can be covered with an abrasion-resistant material. Controlling the cause of abrasion is sometimes an option.
The flash point of a volatile material is the lowest temperature at which its vapours ignite if given an ignition source.
A steel-toe boot is a durable boot or shoe that has a protective reinforcement in the toe which protects the foot from falling objects or compression.
Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical or chemical. The study of wear and related processes is referred to as tribology.
Hydrogen embrittlement (HE) also known as hydrogen assisted cracking (HAC) and hydrogen-induced cracking (HIC), describes the embrittling of metal after being exposed to hydrogen. It is a complex process that is not completely understood because of the variety and complexity of mechanisms that can lead to embrittlement. Mechanisms that have been proposed to explain embrittlement include the formation of brittle hydrides, the creation of voids that can lead to bubbles and pressure build-up within a material and enhanced decohesion or localised plasticity that assist in the propagation of cracks.
Delamination is a mode of failure where a material fractures into layers. A variety of materials including laminate composites and concrete can fail by delamination. Processing can create layers in materials such as steel formed by rolling and plastics and metals from 3D printing which can fail from layer separation. Also, surface coatings such as paints and films can delaminate from the coated substrate.
In materials science, fracture toughness is the critical stress intensity factor of a sharp crack where propagation of the crack suddenly becomes rapid and unlimited. The critical value of stress intensity factor in mode I loading measured under plane strain conditions is known as the plane strain fracture toughness, denoted . Fracture toughness is a quantitative way of expressing a material's resistance to crack propagation and standard values for a given material are generally available.
The salt spray test is a standardized and popular corrosion test method, used to check corrosion resistance of materials and surface coatings. Usually, the materials to be tested are metallic and finished with a surface coating which is intended to provide a degree of corrosion protection to the underlying metal. Salt spray testing is an accelerated corrosion test that produces a corrosive attack to coated samples in order to evaluate the suitability of the coating for use as a protective finish. The appearance of corrosion products is evaluated after a pre-determined period of time. Test duration depends on the corrosion resistance of the coating; generally, the more corrosion resistant the coating is, the longer the period of testing before the appearance of corrosion/ rust. The salt spray test is one of the most widespread and long-established corrosion tests. ASTM B117 was the first internationally recognized salt spray standard, originally published in 1939. Other important relevant standards are ISO9227, JIS Z 2371 and ASTM G85.
Breathability is the ability of a fabric to allow moisture vapor to be transmitted through the material.
In the paint and coating industries, paint adhesion testing is often used to determine if the paint or coating will adhere properly to the substrates to which they are applied. There are several different tests to measure the resistance of paints and coatings from substrates: cross-cut test, scrape adhesion, pull-off test, and others.
Puncture resistance denotes the relative ability of a material or object to inhibit the intrusion of a foreign object. This is defined by a test method, regulation, or technical specification. It can be measured in several ways ranging from a slow controlled puncture to a rapid impact of a sharp object or a rounded probe.
Package testing or packaging testing involves the measurement of a characteristic or property involved with packaging. This includes packaging materials, packaging components, primary packages, shipping containers, and unit loads, as well as the associated processes.
The shelf life of a product can be extended either by adding artificial preservatives or by taking hygienic measures during the manufacturing process. As the consumer trend today is towards preservative-free foods with a long shelf-life, industry is being forced to rethink its manufacturing methods. Instead of adding preservative agents, increased hygienic precautions can be taken during production. A clean and hygienic manufacturing environment is an essential prerequisite in order to keep contamination-related reject rates low. The utilization of surfaces in the manufacturing environment with antibacterial properties can significantly reduce contamination risks.
Decorative laminates are laminated products primarily used as furniture surface materials or wall paneling. It can be manufactured as either high- or low-pressure laminate, with the two processes not much different from each other except for the pressure applied in the pressing process.
Sustainable Slip Resistance is a particular floor friction testing method and selection criteria for use in choosing and sourcing slip-resistant flooring that maintains good tribological characteristics over its life cycle to minimize slip and fall accidents. Testing floors before and after they are in place on a property can assure a building owner that safe flooring has been chosen and installed for its intended use. This floor slip resistance testing method, developed by the McDonald's Restaurant chain and now specified by many other property owners assesses the effects of mild abrasion on wet slip resistance. This test identifies flooring that has a high propensity to lose its wet slip resistance.
Tear resistance is a measure of how well a material can withstand the effects of tearing. It is a useful engineering measurement for a wide variety of materials by many different test methods.
Floor slip resistance testing is the science of measuring the coefficient of friction of flooring surfaces, either in a laboratory or on floors in situ. Slip resistance testing is usually desired by the building's owner or manager when there has been a report of a slip and fall accident, when there has been a report of a near accident, or (preferably) before the flooring is installed on the property. Flooring is tested using a tribometer to discover if there is a high propensity for slip and fall accidents on it, either dry and/or when wet with water or lubricated with other contaminants such as kitchen grease, hydraulic oil, etc. There have been numerous floor slip resistance testing tribometers and lab devices produced around the world to measure both the static (stationary) and dynamic coefficient of friction, but presently there are only a few that have been proven to be reliable for obtaining useful safety results and that have current official test methods. If an instrument has no official published test method, then there is a problem with the instrument, often being poor precision.
Japanese Standards Association is the Japanese industrial standard development organization. JSA promotes standardization and management system in Japan through the following activities:
The Martindale is a unit for quantifying the abrasion resistance of textiles, especially when used for upholstery.
There are two different types of haze that can occur in materials: