Aluminium Pressure Die Casting from the Italian Perspective

Die casting is going through an upswing, with a decisive role being played by research and innovation

by Mario Conserva

The metal foundry segment is globally in good condition, all things considered, with differences between one area of the world and another: China seems to be the dominating country in the market, even in this segment, India is poised to experience considerable growth and this will be at the expense of Japan and Korea whose rating will drop; in the NAFTA area a certain decrease is foreseen, in spite of a significant reindustrialisation process in the US, in Western Europe growth should continue until 2025, with a few signs of the market’s decline beginning to show up in 2020. Germany will gain market share at the expense of its historical competitors (Italy and France) while Poland is growing rapidly; on the borders of the old continent even Ukraine is growing considerably and Turkey confirms its remarkable solidity.
The analysis of the Italian casting foundry sector referring to last year shows a clear upswing condition in the different production departments which is definitely more encouraging than the weak signals in 2016. After a disappointing 2016 for ferrous metal foundry, the upswing, which was already evident for light alloys, began to spread, allowing even the non-ferrous metal department to benefit from an even more dynamic growth rate than the one experienced during the past four years. This growth phase therefore slightly modified the diverging trend in the performance of the ferrous and non-ferrous metal segments, enhanced during the past few years. A condition of considerable weakness persists in the ferrous metal department, especially in the steel foundry segment.

Production statistics
The overall production of castings last year reached 2,236,843 tons, with revenues amounting to 7 billion euros, which implies a much more pronounced growth with respect to the production output in terms of volumes, revenues having grown by 8.6% while tons produced grew by 7.1%. The improvement is evident in many respects, with a marked drive of exports, which grew by 4% in volumes and 7% in revenues considering ferrous castings, but the most decisive drive came from the general improvement of domestic demand. The most pronounced growth (+7.8%) was recorded by the production of cast iron castings, closely followed by the excellent performance of non-ferrous metals with an output which grew by 7.4%, another marked production acceleration, well above the average growth rate of around 4% recorded during the past three years. With these excellent results, the segment went back to a production value of more than one million tons of castings, a level which was reconquered after the deep recession of the 2008-2009 period.
In terms of end use, the production of castings meant for the automotive industry is decisive; this sector continues to show results which are better than the period’s average, confirming its role as a driving segment.

Aluminium castings in Italy and the importance of die casting
The global growth trend involved all compartments of the non-ferrous metal segment, but the main contribution, given its relative clout with respect to the overall Italian production (85%) may be traced back to the increase registered by aluminium castings, equal to 7.4% more with respect to 2016 and to a return to a level of more than 800 thousand tons, second only to Germany which went above 1.1 million tons (Table 1). In Europe the remarkably good behaviour of Poland places it third with over 370 thousand tons f aluminium castings produced in 2017.
In Italy the performance of brass, bronze and copper alloy castings was also good, with a 7.5% increase; the expansion of zinc and alloy castings slightly decelerated, with an increase of 2.2%. Magnesium castings recorded an increase of 8.4%. The overall volumes of non-ferrous castings reached 1,000,095 tons, subdivided into 826,380 tons of aluminium, 72,007 tons of zinc and its alloys, 71,007 tons of brass, bronze and other copper alloys, 8,001 tons of magnesium and other non-ferrous metals adding up to 700 tons. The percentage of die castings is relevant and matches expectations, reaching over 75% of the total production. The automotive segment as usual absorbed 57% of the production of non-ferrous castings and even in 2017 confirmed its role as the most important driver for the non-ferrous metal foundry sector generating a projected increase of castings produced for this sector of 8%. Even in this case a solid positive trend is confirmed for the automotive industry (including vehicles, engines, bodies and components), which began in 2014 and still shows signs of growth for the current year.
Basically, the industry’s scenario is clearly dominated by the demand coming from the automotive sector and transportation in general, with requests for increasingly qualitative, larger and lighter items, with excellent mechanical properties for structural uses. Besides the extraordinary sophistication of the production cycle which we shall also deal with below, this led to a demand for presses with a 5,000-5,500 ton power, a gigantic leap with respect to the situation only a few years ago.
At any rate it is not just the automotive industry which is growing, since in 2017 even other user segments had a positive influence on the production of non-ferrous castings, among them building and construction which showed an interesting increase of 4.2%, and durable goods and electrical engineering, which recorded a growth with respect to last year of 3.8% and 1% respectively. Finally, the increase in volumes destined to the mechanics industry added up to 4%.

The role of research and innovation
The economy is going through an upswing, strongly driven by the automotive industry; die casting foundries definitely recorded before other sectors the change which is occurring in domestic and international scenarios; this, in any case, was the shared feeling perceived during the course of the last couple of years, and these are excellent times for the sector. Aluminium seems to be going through a second springtime, mainly due to the increased demand of cast parts, many being structural parts, from the automotive industries. All OEMs are looking for partners capable of satisfying their increased casting demands; they are also investing in their captive foundry plants, but all are looking for greater supplier capacity.
 Also trucks, buses, trains will have more aluminium die castings, and as a result, we see many new projects coming out. Think of the engine evolution: from diesel gasoline engines to hybrid and fully electric vehicles, totally different engines and cars, with different aluminium parts. Probably less kilos, but more complicated and thinner parts, and the question is whether we are ready for these changes.
In this context, the maintenance of the technological leadership position is very important for the aluminium foundry industry in Italy and Europe, and particularly in the die casting segment, which is subject as we know to continuous stimuli from the automotive industry which is its main client; this is not just on account of demands regarding lightweighting and E-Mobility, which is significantly changing the supply chain especially regarding the drive train; besides these issues, vehicle manufacturing companies also request certificated quality and an accurate programming of quantities, besides a service from their suppliers which must be increasingly tailored to their demands, such as productions relocated outside Italy and the need to be close to the client, which implies, for the supplier, investments and costs regarding logistics. In this situation, it is definitely necessary for this segment to look at innovative breakthroughs to remain competitive, working on the growing complexity of the metallurgy of materials and on the trend towards the supply of fully machined castings. Actually many research projects are ongoing in many Italian machine and die casting manufacturing companies, cooperating with the most important and prestigious universities, from Milan and Turin’s Polytechnics to the University Institutes of Brescia, Padua and Vicenza, Bergamo, Bologna, Modena and Ferrara, just to mention some of the most important institutions which have been focusing for some time on themes lined to aluminium, following especially two work strands, regarding production technologies and the metallurgical improvement of the aluminium alloys to be used.

High performance die castings
Regarding the first issue, a project should be mentioned to begin with: “Thin-walled aluminium die casting”, for a next generation product/process innovation of aluminium die casting technology, aimed at obtaining components with very thin walls (target 1.8 mm vs. 2.5 mm), in a near net shape configuration, for a significant reduction in machining, and the positive results of weight reduction and topological optimization by means of the introduction of cores, and/or metal foam inserts (A&L, n° 1/ 2017). The main scopes of such projects are those of strengthening an industrial system, which allows to maintain a relevant foothold on industry-intensive segments which in the past had been considered “mature”, with a production content which had often been relocated to emerging countries, with an impact on all connected activities (services, engineering, supplies, logistics, validation) and on employment sources. In many cases the real value of the projects, irrespective of the final results, is the capacity of generating in the very complex industrial chain, the right connection of solutions thanks to an integrated system of companies and a very synergic approach, which will be derived from the presence of the necessary engineering competence, experimental equipment, industrial experience and production capacity.

The Industry 4.0 challenge
A second important research and development domain applied to die casting by the Italian operators in this segment is the one which involves reaching the requisites set by Industry 4.0 applied to the pressure die casting sector (A&L n°2 /2015; A&L n°2/ 2017; A&L n°3/ 2017); it is a concrete reality, the outcome of years of development and research aimed at maximizing the efficiency of the casting cell, the press being by all means the throbbing heart of this unit. This is not a revolution, but a logical evolution of the past good technology: digitization and interconnection now allow a very fast and inexpensive data processing. Even in the past, production and process data were collected in the die casting foundries, but this was done more empirically and subjectively and over long time periods. Decisions were often made by those with more clout and not based on data and deviation trends of the process parameters. The matter, in theory, is very simple, but the problem is evidently how to transpose it to operational practice. To reach the goal of the intelligent cell, we must begin with a simple, standard and reliable product, so as to limit the amount of data required. Then, the next step is to connect to the press the auxiliary apparatus, furnaces, moulds, heat regulation control panels and mould lubrication systems. Their control must be integrated into the control panel of the press, creating a hub for the Foundry 4.0 world. The last step is making the press intelligent, fitting it with a complete system of sensors for a timely and continuous monitoring of the most important functions, which guarantee quality and the highest production efficiency.

New die casting alloys
Many other research and development themes, besides the ones mentioned above, during the past few years have been on the agenda of the main operators of the die casting sector in Italy, from machine manufacturers to foundries, to research institutes, to end users, it is impossible to mention them all, I would just like to touch upon the central metallurgical topic which concerns the fine-tuning of the optimal chemical composition of aluminium alloys for die casting. In the recent history of aluminium alloys, right up to a few decades ago, only plastic transformation alloys used to produce extrusions or rolled products were the object of serious metallurgical studies, now even alloys for foundry castings benefit from the interest of manufacturers and metallurgists. This is a focal topic because it aims at obtaining alloys for die casting which are economical from a production standpoint, therefore manufactured with recycled metal, but at the same time easy to cast, suitable for the production of complex castings, with thin walls, free from flaws, which may be hardened with simple heat cycles and capable of providing finished castings with good strength properties, with high ductility and good values of fracture toughness. As we know, the creation of new alloys is a complex issue because reaching the objective depends on precise trial procedures, checks and certifications, therefore it is premature to talk about concrete results today. But it is a fact that the large number of ongoing projects in Italian companies and universities on the subject will lead in the coming years to a sizeable enrichment of knowledge to open up new uses for die castings.
It is finally important to mention the launch of two relevant educational initiatives in Brescia by AQM and CSMT a few years ago, the High Pressure Die Casting School and the Low Pressure Die Casting School, to satisfy the need for a generational change in the strategic technical and organizational roles of die casting foundries, filling the training gap of traditional school and university syllabi and stimulating dialogue between the production and design worlds. It is clear that with this initiative the Italian companies in this sector and all those connected with the machining, transformation and use of die castings may find in this new school a catalyst to encourage innovation, benefiting the county’s competitiveness, as well as a formative path for future managers of key processes, considering technical and productive requirements within the context of legal and management requirements.
The conclusion is that in the perception of the Italian market there are threats but also a lot of opportunities for foundry die casting operators mainly due to the growth of demand for light alloy details and components for the automotive industry in the global market. In actual fact aluminium applications are booming and all OEMs have been redesigning for many years their vehicles to meet the new severe CO2 standards. Not only aluminium wheels, engine parts and transmission, but also suspension components, body in white structural parts, seat and door frames, will be commodities in the coming years.
The answer of Italian operators in this segment has been clear with a sharp peak in research and development activities in partnership with many Italian Universities, many good results have already been obtained, others may be expected in the years to come for an optimal consolidation of this industry.