It keeps going and going.TD process extends tool life in shearing and piercing applicationsProlonging the life and performance of tooling can increase productivity and reduce tooling and tooling maintenance costs. To reduce wear and increase tooling life, many in the metalforming and shearing industries use tool treatment processes and coatings. One of the tool treatment processes metalformers use is the Thermal Diffusion
Because the VC layer is diffused into and onto the tool substrate, TD significantly reduces galling, wear, seizure, and corrosion and provides superior peel strength and adhesion strength. It extends the life and performance of dies, punches, and tooling used in the stamping and forging industries by 5 to 50 times or more. TD is effective with air-hardening cold and hot working die steels such as A2, D2, and H13, high speed steels, and cemented carbides carbides (kar´bīdz), n 1. in chemistry, carbon binary compounds with strong electron-releasing properties. 2. mixtures of carbon with at least one heavy metal. E.g. . Although cemented carbides are very hard, they still tend to gall and can benefit from TD. The steels should have a 0.3% or greater carbon content and tolerate temperatures of 1600F and above. The tool treatment process is used in such industries as metalforming, appliance, die casting die casting Forming metal objects by injecting molten metal under pressure into dies or molds. An early and important use of the technique was in the Linotype machine (1884), but the mass-production automobile assembly line gave die casting its real impetus. , wire making, and automotive stamping. To this point, however, TD is not widely used in shearing type applications. There is a misconception mis·con·cep·tion n. A mistaken thought, idea, or notion; a misunderstanding: had many misconceptions about the new tax program. that since the VC layer is so hard and brittle that it will not perform well in shearing applications. This means that many in the metalworking industry are not aware that TD can help them reduce wear and extend tool life. Field tests show that even in very severe shearing conditions, for example, the production of safety belt buckles This article is about the comic strip. For the fastener, see Buckle Buckles is a comic strip by David Gilbert about the misadventures of a naïve dog. Buckles debuted on March 25, 1996. from HSLA steel HSLA steel (high strength low alloy steel) is a type of steel alloy that provides many benefits over regular steel alloys. In general, HSLA alloys are much stronger and tougher than ordinary plain-carbon steels. , TD can help reduce wear and extend tool life in piercing shear applications. In the test, the behavior of TiN-PVD coated D2 punches, VC-TD treated D2 punches, and uncoated D2 punches was observed. All punches were used in piercing, blanking a hard steel, austempered bainitic steel with oxide film, Hv 360. In the tests, after 10,000 hits, he cutting edge of shearing punches treated with TD showed only a steady wear of the VC layer. There vas no large chipping and spalling. The tests further showed that TD helped reduce wear at both 15% and 5% die clearances. (Fig 1). Test conditions * Steel coil size: 0.6299" (16mm) wide and 0.0394" (1mm) thick. * Coatings: Arc Evaporation evaporation, change of a liquid into vapor at any temperature below its boiling point. For example, water, when placed in a shallow open container exposed to air, gradually disappears, evaporating at a rate that depends on the amount of surface exposed, the humidity PVD PVD abbr. peripheral vascular disease PVD Peripheral vascular disease, see there for TiN and TD for VC * Dies: No coating * Lubricant Lubricant A gas, liquid, or solid used to prevent contact of parts in relative motion, and thereby reduce friction and wear. In many machines, cooling by the lubricant is equally important. : Machine oil * Stroke: 30/min * Clearance: 5% and 15% * Number of hits: 10,000 Test results Test results revealed that the TD-treated punch showed reduced wear on the treated surfaces as well as on the face of the tooling where it was not treated with TD. As a result, the burr burr (bur) bur. burr n. Variant of bur. burr 1. a plant seed capsule carrying many hooked structures which catch in animal coats thus promoting dissemination of the plant. height on holes pierced pierced adj. 1. Cut through with a sharp instrument; perforated. 2. Of or relating to a body part that has been perforated for the purpose of attaching a piece of jewelry. 3. by the TiN-coated punch is larger than on holes pierced by the TD treated punch (Fig 2). Observation of the surface and cross section of the punches after 10,000 hits showed that the TiN coating at the cutting edge had locally spalled off and the steel substrate had been exposed. The TD treated punch showed no spalling. The TD treatment on the cutting edge of the punch wore, showing a very smooth contour contour or contour line, line on a topographic map connecting points of equal elevation above or below mean sea level. It is thus a kind of isopleth, or line of equal quantity. . This means there was no chipping or spalling of the VC layer even at the edge of the TD treated tooling. In the tests, the wear of both the TiN-coated punch and the TD-treated punch was less than that of the uncoated punch. The degree of edge wear after 10,000 hits at both 15% and 5% clearance can be observed in Fig 1. Results at 5% clearance At 5% clearance, where the loading conditions on the punches was much more severe than at 15% clearance, the difference between TD treated tooling and TiN-PVD was even more significant. The closer; 5% clearance produces more severe loading on the punches. Increased force is needed to push the blank into the die and to withdraw the punch from the hole. The longer shearing length also generates more punch side wear. Even under these severe conditions, the TD-treated punch showed much less wear than the TiN-coated punch or the uncoated punch. The forces encountered with close clearances, especially with hard work materials, can cause other types of damage as well. Here, too, the TD-treated punch showed minimum wear. Microscopic observation of the TD-treated punch after 10,000 hits at 5% clearance did, however, reveal damage from cracking and loss of the VC layer on the flank surface of the punch about 0.15mm above the cutting edge. This type of damage is formed only when substrates are deformed de·formed adj. Distorted in form. plastically by an applied stress that is larger than the compression yield strength of the substrate materials. In this instance, the plastic flow and cracking in the substrate were evident. To address the problems created by severe conditions, it is recommended that higher strength substrate materials, such as high speed steels, PM steels, and even cemented carbides rather than A2 and D2 be used. The higher strength substrate coupled with TD treatment can help reduce the types of damage discussed above. |
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