How to reduce mold wear and increase mold life during titanium alloy hot stamping?
Publish Time: 2025-03-03
Titanium alloy is widely used in aerospace, automobile manufacturing and medical equipment due to its high specific strength, corrosion resistance and high temperature resistance. However, due to the high temperature forming characteristics of titanium alloy, the mold is susceptible to wear during hot stamping, resulting in increased production costs and shortened mold life, which in turn affects production efficiency. Therefore, how to reduce mold wear and increase mold life has become an important topic in the optimization of titanium alloy hot stamping process.1. The main cause of mold wear during titanium alloy hot stampingInfluence of high temperature environment During the hot stamping process, the mold is exposed to a high temperature environment of 600℃~900℃ for a long time, which causes thermal fatigue and softening of the mold material and aggravates wear.Titanium alloy with high chemical activity easily reacts chemically with the mold material at high temperature, forming adhesive wear, making the mold surface rough and reducing durability.The friction between titanium alloy and the mold surface with a higher friction coefficient is large, causing serious mechanical wear during the forming process.Difference in thermal expansion coefficients The different thermal expansion coefficients of titanium alloy and mold material lead to uneven stress between the mold and the workpiece, resulting in cracks and accelerating mold damage.Stress concentration and fatigue damage During hot stamping, the mold needs to withstand a large stamping force. Long-term use may cause stress concentration, leading to fatigue damage and cracks in the mold.2. Optimization measures to reduce mold wear and increase mold life(1). Select high-performance mold materialsSelecting suitable mold materials is the key to increasing mold life. The main high-performance mold materials currently used include:Hot work die steel: has good high-temperature strength and toughness, and can resist thermal fatigue.Ceramic-based composite materials: excellent high-temperature resistance and oxidation resistance, can reduce mold adhesion wear.Cemented carbide (WC-Co): has high hardness and wear resistance, suitable for hot stamping of high-strength titanium alloys.(2) Optimize mold surface treatment technologyAdopting advanced surface treatment technology can significantly improve the wear resistance and adhesion resistance of the mold:Plasma nitriding: Form a high-hardness nitride layer on the mold surface to improve wear resistance.Ceramic coating (TiN, TiAlN): Reduce the adhesion between titanium alloy and the mold, improve wear resistance and oxidation resistance.Laser surface strengthening: Enhance the surface hardness of the mold through laser treatment and extend the service life.DLC (diamond-like carbon coating): Provides an extremely low friction coefficient and reduces friction and wear.(3) Improve lubrication methods and reduce friction and wearSince titanium alloys are easy to adhere, optimizing lubrication methods can effectively reduce mold wear:Use high-temperature solid lubricants (such as MoS₂, BN) instead of traditional lubricants to improve lubrication effects. Use self-lubricating mold coatings to reduce direct wear of titanium alloy on the mold. Add microporous structures to the mold surface to enhance the adhesion of lubricants and extend the lubrication time.(4) Optimize mold design and reduce stress concentrationBy optimizing the mold structure, the damage to the mold caused by the punching pressure can be reduced and the mold life can be improved:Use progressive forming design to reduce the single punching load. Add a cooling system to control the mold temperature and avoid thermal fatigue. Use optimized flow channel design to ensure uniform material flow and reduce local stress concentration.(5) Accurately control hot stamping process parametersReasonable control of process parameters such as temperature, pressure, and forming speed can effectively reduce mold wear:Reduce stamping temperature: Control within the optimal forming temperature range (usually 600℃~850℃) to avoid mold overheating.Reasonable pressure distribution: Use multi-level pressure control to reduce local mold stress and improve durability.Optimize stamping speed: Appropriately reduce stamping speed, reduce frictional heat, and improve mold stability.(6) Strengthen mold maintenance and monitoringThrough intelligent monitoring and regular maintenance, the service life of the mold can be effectively extended: Use an online monitoring system to detect mold temperature and stress state in real time to prevent abnormal wear. Regularly polish and repair the mold to reduce the impact of surface microcracks on service life. Set the mold replacement cycle to prevent mold failure due to excessive use.In the titanium alloy hot stamping process, mold wear is a key issue affecting production cost and efficiency. By optimizing mold materials, surface treatment, lubrication methods, mold design and process parameters, mold wear can be effectively reduced and mold life can be increased. In the future, with the development of intelligent monitoring, new high-temperature resistant materials and green lubrication technology, the durability and performance of the mold will be further improved, providing a better solution for efficient and low-cost titanium alloy forming.
