Case Study Increasing Die Casting Productivity and Reducing Costs
As manufacturers within the automotive industry strive to meet the challenges of a competitive global marketplace, the die casting industry is undergoing a period of change and development. One option could be a Lubrolene water-free die-release technology that provides manufacturers with quality, cost, productivity and environmental benefits.
In recent years there was a shift towards lightweighting in the automotive industry with increasing use of aluminum for powertrain components and a rapid growth in aluminum structural components such as shock towers, rails and torque boxes. In fact, structural casting is now being adopted in higher volume, mid-sized vehicle platforms that need to be manufactured to a consistent quality in multiple global locations.
Fundamental in delivering that functionality is the process of die casting. Supporting manufacturers to move away from multi-component welded assemblies for vehicle structures, high pressure vacuum die casting technology is able to provide a complex, one-piece structural component, significantly reducing the assembly, number and weight of components in a vehicle. In practice, substituting traditionally steel components with lightweight, one-piece structures contributes significantly to reduced vehicle weights. That means greater efficiency, reduced fuel consumption and lower levels of CO2 emissions – all key focusses for automotive manufacturers as legislation around the world places greater emphasis on fuel efficiency, emissions and the environmental impact of vehicles.
Further to this, lightweight structures, and the weight reduction associated, are essential for the increasing adoption of electrified vehicles. A segment of the market forecast to grow strongly in the medium term, major OEMs are investing significantly to develop the necessary technology cost-effectively.
Developments in die casting technology have facilitated the design of larger, more complex, structural components which assist the automotive industry with its weight reduction goals. This approach accommodates larger components such as door and window frames, instrument panels and cross members to be produced by die casting, and has led to a trend toward larger die casting machines and increasing shot weights.
However, the complexity of large one-piece components makes it difficult to design internal cooling which successfully reduces the temperature of all parts of the die uniformly. This can lead to localised hot spots and solder problems.
Lubricants as Possible Solution for Die Casters
To avoid compromising quality and increasing costs in the creation of large, complex components, specifying the correct die casting lubricant is essential to ensure an adequate release lubricant film is formed over the die surface. However, the surface temperature of the die makes this difficult with water-based lubricants. To ensure the oil film is successfully formed on the die surface some water-based lubricant will remain in the die cavities. This may cause porosity problems and water stain on the casting surface. Whilst residual water on the die surface can be dried using compressed air, this extends cycle times and is a costly consumer of electrical energy, increasing processing costs.
For an industry looking to cast larger components with higher process temperatures and also meet the challenges of maintaining product quality, improving productivity and reducing costs, Lubrolene WFR provides a possible solution. Significantly reducing the quantities of lubricant required, Lubrolene negates the need for die cooling by lubricant and delivers a high adhesion efficiency for thicker and more effective film formation. Quality is improved through better molten metal flow and reduction of the quantity of trapped gases due to no external water-cool, as well as the fact that WFR can be applied at higher temperatures than conventional water-based lubricants, meaning there is less thermal stress on dies. The avoidance of heat cracks extends the service life of the dies significantly – the major source of savings.
With cavities increasingly present in complex pieces, Lubrolene WFR-EC – which features an electrostatic charge – ensures an effective release. Creating a wrap-around effect, the electrostatic charge delivers consistent, uniform coverage, irrespective of die complexity. Using a specially-developed electrostatic spray gun, the application of Lubrolene WFR further reduces soldering problems, providing full, unrivalled coverage. Once the practicalities of complex, one-piece die casting are resolved through the implementation of new technologies and solutions, the benefits for automotive manufacturers begin to emerge fully.