Formability is the materials ability to be shaped in to semi-finished and finished products by manufacturing techniques like rolling, forging, extrusion, deep drawing, etc. Many transportation equipment like cars, trucks, air planes, etc., use thin sheet metals generally steel and aluminum alloys formed in to respective shapes by processes such as deep drawing, bending, etc., and joined to each other to make an envelope. With increasing need for light weighting the equipment for fuel efficiency, many sheet metal producers are engaged in material developments like alloy development, coating development, etc., to improve the formability of high strength and light gage products. Both the sheet metal producer and fabricators need to know if a material can be formed in to the shapes required by traditional processes to form the body envelop of a car, truck or air craft, etc. These operations are done at ambient temperature or warm temperatures, but at high process speeds. This cold formability is very critical for component manufacturing. Equally several finished, semi-finished metal product manufactures like forging, extrusion companies and flat rolling companies would like to understand the formability of materials specifically metals and alloys. These operations are generally done at high temperatures. Thus, hot formability or warm formability of the materials is also important. These are assessed using simple tests like tensile tests, compression test, torsion test, bending test, drawing test, etc.
Formability testing is divided in to two main groups namely cold formability, Hot and warm formability. Cold formability is important for majority of forming done at room temperature. Typical examples are can manufacturing, autobody sheet pressing, etc. It is generally assessed by simple tensile test or bend test. One can determine materials parameters like ductility, strain hardening exponent (n value), and draw ratio (r value) from a simple tensile test. Additional tests would involve cupping test or limiting dome height (LDH) draw test and forming limit diagram (FLD) test. In addition to it there are tests like guided bend test, stretch bend tests, etc., used to assess hemming and bending formability of sheet metals. These tests are limited to generally thin gage materials. In addition to assess bulk formability for hot forming tests like hot compression or torsion tests are done at a variety of test speeds.
Capability – At TTL, we have capability to run the following formability tests at ambient and non-ambient conditions.
Some relevant standards:
Flexural or bending test measures the bending behavior of beams or beam like samples. In this a rectangular bar type sample is supported on two fulcrum points, while the span will be loaded at one or two points subjecting the sample bending loads. Stress patterns in flex testing are complex unlike in tensile or shear… Continue Reading
Product testing generally refers to testing finished products before being shipped to customer or consumer. It differs from material testing in that an additional aspect of product geometry, product surface, etc., their influence on the product performance is tested. Some well-known examples of product testing are automotive crash testing to assess crash worthiness of the… Continue Reading
Touchstone is committed to providing its customers with quality, reliable test results. That is why we have undertaken the rigorous steps needed to meet and secure the most stringent of test lab accreditations including ISO/IEC 17025, NADCAP 7101 (Materials Test Lab) and NADCAP 7122-I (Non-Metallics Materials Testing).