History of Metal Testing
Some of the earliest forms of metal bar scratch testing date back to about 1722. These tests were based on a bar that increased in hardness from end to end. The level at which the material being tested could form a scratch on the bar was a determining factor in the specimens hardness.
Until the 1800s, railways were constructed of cast-iron and was prone to rust and it was brittle, often causing it to fail under stress. In the early 1840s, William John Macquorn Rankine examined many broken railway axles and discovered that the axles had failed due to the progressive growth of a brittle crack from a shoulder or stress concentration on the shaft.
In 1903, Sir James Alfred Ewing KCB studied and named the phenomenon of hysteresis. He also studied the crystalline structure of metals, and in 1903 he was the first to propose that fatigue failures originated in microscopic defects or slip bands in material.
Why do we need to test on metal?
Metal testing is a process or procedure used to check composition of an unknown metallic substance. There are destructive processes and non-destructive processes.
Metal testing can also include, determining the properties of newly forged metal alloys. With many chemical-property databases readily available, identification of unmarked pure, common metals can be a quick and easy process. Leaving the original sample in complete, re-usable condition. This type of testing is non-destructive.
Metal fabricators are challenged to provide materials to the automotive, aerospace, and construction sectors that have the right strength and ductility. These sectors follow stringent safety regulations. The performance of their materials are a matter of life or death. Cars and airplanes cannot fail, and buildings must stay standing.
What are the benefit of metal testing?
Our team polishing Metal in our testing laboratory
1) To identify the characteristics of a metal
When manufacturing a product out of a metal, it is crucial to understand the properties and characteristics of the metal. It is important to identify how they will react with other metals, whether they are suitable to certain environments, and if they are strong and durable. Once the characteristics of the metal have been understood, it is easier to manipulate it during manufacturing processes. One of the way is Positive Material Identification (PMI), it is a fast and non-destructive testing (NDT) method for verifying the chemical composition of metals and alloys.
2) To identify flaws in metals
A flawed metal cannot be used in manufacturing processes. Metal testing lab uses comprehensive procedures to detect any flaws in metals. Various testing methods can be used to detect flaws such as cracks or deformations within the metal. Liquid penetrant test uses the capillary force of a liquid that is absorbed into cracks in the material surface.
3) To check whether they are compliant with the standards
Metal parts and metals need to meet certain safety standards that are imposed by regulatory bodies. This is best understood when a metal is subjected to metal testing. Metal testing enables the detection of toxic elements like Mercury, Lead, and other harmful heavy metals within the metal. It is important to check whether metals are compliant with standards otherwise it can affect the manufacturing processes and disrupt a number of industries.
The ability to purchase materials with defined properties and a recognized level of quality reduces the risk of incompatibility or failure, and ensures that products perform as intended. Using standards also helps businesses demonstrate to regulators and customers that their products and services meet defined safety, quality, and environmental standards.
Improved ability to meet legislative and regulatory requirements enables companies to develop competitive manufacturing capabilities and expand their market reach by ensuring conformity with various industry, military, aerospace, and automotive standards.
4) To check the dimensions of the metal
Different manufacturing processes require different dimensions of materials to function smoothly. Advanced metal testing techniques help characterize the dimensions of the different metals in use and help to categorize them for various uses. By carrying out dimension test, companies can prevent potential product failure in manufacturing.
5) To check if the metal is weather resistant
Metals that are used in manufacturing industries need to be highly durable and resistant to a variety of weather conditions. If a metal corrodes or disintegrates in a specific type of climate, metal testing laboratory enables to identify such climates and also helps in developing techniques that ensure that the metal can tolerate all kinds of climatic conditions. Salt spray testing is used to assess the durability of finishes and coatings on metal surfaces. The test is carry out in a highly corrosive atmosphere.
6) To test the soundness of metals
Soundness of a metal indicates that the metal has no cracks, shrinkages, or cavities within it. If a metal is not sound, then it can lead to failure in manufacturing with a number of harmful outcomes. Metal testing labs processes help to detect such flaws in metals before they are used in any major manufacturing processes. This is important because if a metal is unsound, it can lead to failure in manufacturing or use. Metal testing will find these flaws before the manufacturing process begins.
7) To test how easily the metals corrode
If a metal corrodes easily, then it cannot be used reliably in structures of any kind. This is why metal testing lab uses certain corrosion tests to see how corrosion resistant the surface of any metal is. This determines the extent up to which a metal can be used in manufacturing. The assessment of a new type of alloy in different types of environments to compare with conventional commercial alloys; an estimation of an inhibitors’ efficiency in reducing the corrosion rate of metals; and understanding the mechanism of corrosion are the other reasons.
8) To test the load bearing capacities
Metals in manufacturing industries need to have excellent load bearing capacities. This makes sure that the structures that are using the metal do not collapse or weaken in strength. Metal testing laboratory uses several tests to determine the fatigue point of a metal. The metal is tested with different loads and the localized damage that occurs with each load is noted. Based on these results, the metals are classified into how and where they can be used in different manufacturing processes.
As there are more complicated welding joints for heavy steel plate used in large boilers, pressure vessels or ship hulls and decking, the Crack Tip Opening Displacement (CTOD) test is use to determine fracture toughness of a material with a crack.
How has metal revolutionized the way we live?
Chef holding a steel tong and frying on a steel pan in a Restaurant Kitchen
One of the metals which truly revolutionized the human civilization is Stainless steel. With its sleek, shiny surface and tremendous strength, it has revolutionized most modern industries, including food, medicine, and transportation. The non-corrosive and rust-resistant properties of stainless steel have made it essential in the preparation, delivery and storage of food.
Stainless steel is a standard in modern restaurant kitchens since it can be easily cleaned and dried. The surface of stainless steel resists oxidation at high temperatures, making the sterilization of medical instruments possible. Its light weight and durability allowed the development of streamlining in transportation.
The streamlined design of new trains, planes, and automobiles allowed for less wind resistance, and trains such as the Zephyr helped spark a new design movement. Everything from toasters to vacuum cleaners emulated the new vehicles. Stainless steel paved the way for modern technology and continues to influence our lives every day.