- Radio frequency identification (RFID) and Bluetooth communication for die tracking
- Dunnage rack and material-transfer cart tracking by means of high frequency (HF) and ultra-high frequency (UHF) communication technologies
- The use of industrially robust RFID systems for shut-height validation for dies, and new mechatronic systems for monitoring progressive-die processes and value-added in-die validation and error-proofing
- Rapid die-change technologies using remote energizing and information transfer via wireless couplers on transfer dies and in progressive-stamping dies.
On the materials side, automakers have employed advanced high-strength steels (AHSS) for nearly 30 years now. More recently comes production of ultra-high strength metal stampings via cold forming and hot stamping processes. Processing stampings from aluminum generally requires a different approach as compared to steel. While many aluminum sheet alloys are easily cold formed, difficult alloys can benefit from warm forming or hot stamping processes. These technologies, once limited only to research labs, have emerged as viable forming processes in some metal forming plants.
Pressure On Tool Builders
On top of these disruptive technologies, tool-build operations face constant pressure to shorten lead times and optimize die designs while also reducing errors. Material loss in metal stamping operations generates one of the largest recurring costs in the manufacturing process, and reducing process waste is paramount to lowering OEM production costs and increasing profitability for the supplier. Modern computer-simulation technology allows die engineers to more accurately predict blank size and optimize layout within a coil. Accomplished early in the planning stages, predictions then must be further optimized using additional planning tools to define and validate the process through simulation, maximizing the benefits. Simply achieving “green” (safe) simulation results no longer meets the objective for today’s automotive tool-and-die supplier.
Tool-steel selection and best practices (heat treatment, grain orientation, etc.) for forming, trimming and piercing of AHSS grades are required for cold and hot stamping, with choice of the right tool steel a difficult decision. Factors affecting such decisions include steelmaking practices, grade characteristics, heat treatment processes, quenching atmosphere, tempering temperatures, microstructure, surface coatings and the impact of die-manufacturing practices on tool performance. Gone are the days when die shops simply decided between O1, A2 and D2.
Surface treating for large automotive and appliance tool steels may benefit from an operation consisting of controllable electromagnetic hammer heads imparting rapid reciprocal motion of a striker ball against the die surface, known as machine hammer peening. Machine hammer peening may eliminate manual polishing in dies and molds; improve wear resistance by increasing hardness in the surface layer; reduce friction in deep drawing applications; and potentially eliminate secondary processes such as heat treating, coating and nitriding. Where such processes already are applied, peening improves the results.
Laser heat treating describes a process in which a laser beam focuses onto the tool-steel surface being treated. With proper control, the laser energy raises the surface temperature above its martensitic-transformation temperature. When the beam switches off, the thermal mass of the die section promotes rapid self-quenching, resulting in formation of the desired martensite microstructure and giving the material its required hardness and wear properties. This process increasingly has become popular due to precision control and application of heat to localized areas, resulting in minimal distortion and residual stress input.
Testing various metal forming lubricants for comparison can be time-consuming and risky to production tools, with many lubricant formulations based upon wet-bench chemistry, not actual field trials in an actual tool. Lubricant suppliers and manufacturing companies can take advantage of standardized cup-draw-test tooling to evaluate results for a variety of trial lubricants and sheet metal substrates. This may prove an especially important step in lubricant selection when processing different grades of AHSS materials. Test results show correlation to real-life press applications, thus limiting the risk to actual tools.
Real-time nondestructive production-monitoring tools have been used widely for various manufacturing processes such as joining and fabrication. And now being realized: applications of real-time and nondestructive evaluation tools to monitor and assess incoming coil properties, blank surface finish/lubrication, die stresses, part temperature, final stamping quality such as springback and geometry tolerances.
Eventually, your company or die shop must deal with disruptions created by new technology. Your response will be determined by how you perceive these disruptions. MF
Industry-Related Terms: Alloys
, TransferView Glossary of Metalforming Terms
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