Review on additive manufacturing of tooling for hot stamping

Abstract

Sustainability is a key factor in an automotive OEMs' business strategy. Vehicle electrification in particular has received increased attention, and major manufacturers have already undertaken significant investments in this area. However, in order to fully confront the sustainability challenge in the automotive industry, lightweight design in additional to alternative propulsion technologies is also required. Vehicle weight is closely correlated with fuel consumption and range for internal combustion and electrified vehicles, respectively, and therefore, weight reduction is a primary objective. Over the past decades, advanced steel and aluminium-forming technologies have seen considerable development, resulting in significant weight reduction of vehicle components. Hot stamping is one of the most established processes for advanced steel and aluminium alloys. The process offers low-forming loads and high formability as well as parts with high strength and minimal springback. However, the high temperatures of the formed materials over numerous cycles and the significant cooling required to ensure desirable component properties necessitate advanced tooling designs. Traditionally, casting and machining are used to manufacture tools; although in recent years, additive manufacturing has gained significant interest due to the design freedom offered. In this paper, a comprehensive review is performed for the state-of-the-art hot-forming tooling designs in addition to identifying the future direction of Additive Manufactured (AM) tools. Specifically, material properties of widely used tooling materials are first reviewed and selection criteria are proposed which can be used for the transition to AM tools. Moreover, key variables affecting the success of hot stamping, for example cooling rate of the component, are reviewed with the various approaches analysed by analytical and numerical techniques. Finally, a number of future directions for adopting additive manufacturing in the production of hot stamping tools are proposed, based on a thorough analysis of the literature.

Copper additive manufacturing using MIM feedstock: adjustment of printing, debinding, and sintering parameters for processing dense and defectless parts

“…In the last few years, several researchers have thus explored beamless AM methods for the fabrication of metal parts. Some methods combine polymer 3D printing and other conventional manufacturing processes such as casting, sintering, electroforming, and spraying [8][9][10][11][12][13]. This opens the way to the fabrication of metal parts at low cost due to less capital investment, less material consumption, and low-skilled worker requirements.…”

Analysis of Hot Stamping Tool Cooling System—A Case Study

“…They have, first, a more even temperature distribution on the tool surface and the lack of thermal bridges has a positive effect on their wear. This problem is discussed in works [ 15 , 16 , 17 ] which highlight a significant improvement in cooling conditions for molds made in additive technologies. This translates into the quality of the drawpieces.…”

Internal face finishing for a cooling channel using a fluid containing free abrasive grains

“…Generally, a conformal cooling channel is located inside the mold to reduce the cycle time [3]. Meanwhile, an additive manufacturing (AM) technique called selective laser melting (SLM) has been developed in the die and mold industries [4]. SLM enables the incorporation of features that would have been cost prohibitive or even impossible with traditional manufacturing techniques, such as the use of internal cooling channels to improve the cooling performance.…”