Undeniably, thanks to the global Covid-19 pandemic, the North American PM industry endured one of the worst periods of declining production and sales (metal powders, equipment, and parts) in its history. During the pandemic, manufacturing in North America was disrupted, hitting the PM industry especially hard, as the automotive industry, the primary consumer of PM parts, came to a standstill. Shelter-in-place mandates resulted in more people cooking at home and provided time to renovate kitchens, garages, and laundry rooms. This was great for PM suppliers to small and large appliance manufacturers, until inventories of finished goods were exhausted, as assembly lines were shut-down due to the mandates.
Healthcare providers were constantly in the news, receiving the praise that they deserved for going above and beyond, treating those that required medical assistance because of this horrible virus. However, many elective surgeries, those that required metal injection molding (MIM) components, were postponed, stalling deliveries, and increasing inventories. The North American oil rig count, an important barometer for the drilling industry, dropped more than 50% in 2020, compared with 2019. When drilling rigs are active, supplying many industries that rely on petroleum-based products, they consume tungsten carbide inserts for drill heads, made from metal powders, but again, demand was not required.
This is just a small example of how the PM industry was impacted by the pandemic. The trickledown effect resulted in a flurry of cost-cutting solutions, including wage and benefits cuts, furloughs, permanent lay-offs, retirements, and temporary plant closures for facilities deemed as non-essential. Some government programs, such as the Paycheck Protection Program, helped many small to medium enterprises stay afloat, while other programs intended to help the displaced workforce became a hinderance, as some displaced workers received more money for staying home, and did not return when they were called back to work.
However, the PM industry is a resilient consolidation of many forces, which found its inner strength to rally, and became stronger as a result of these turbulent times. I am unaware of a single North American PM company that permanently closed its operations as a direct result of the pandemic. Many companies’ representatives report that their organizations are working mandatory overtime due to shortages of skilled workers and engineers, while setting new production levels because of pandemic induced solutions. We are all survivors, and the PM industry is still alive and well, landing back on its feet, well on its way to recovery. Let’s take a deeper dive.
Metal powder shipments
Metal powder shipments started off decently for 2020 before falling drastically in April and May but started recovering in June. When the final numbers were tallied, the total North American metal powder shipments declined by an estimated 19% to 332,833 mt (366,960 st).
Total iron powder shipments decreased 19.1% to 284,845 mt (314,052 st), wPM and friction grade powder shipments were down 19.4% to 258,220 mt (284,697 st). Welding applications dropped by 20% to 10,993 mt (12,120 st). Cutting, scarfing, and lancing applications declined by 21.9% to 679 mt (749 st). Miscellaneous uses declined 13.9% to 14,953 mt (16,486 st).
Stainless steel, copper, nickel, and aluminum powder shipments all declined by an estimated 18 to 21%. Estimated shipments for 2020 include: stainless steel powder, 5,714 mt (6,300 st); copper and copper base powder, 12,517 mt (13,800 st); nickel powder, 4,082 mt (4,500 st); and aluminum powder 19,047 mt (21,000 st).
Molybdenum shipments declined an estimated 15.4% to 422 mt (465 st). Tungsten powder shipments decreased by an estimated 1.4% to 1,510 mt (1,665 st), and tungsten carbide powder shipments decreased an estimated 34.6% to 4,696 mt (5,178 st).
Conventional press and sinter
The demands for products containing conventional press and sinter PM surged during the second half of 2020, and it has continued to move in a positive direction since. Disrupted supply chains resulted in the re-shoring of some PM parts, but not to the extent that most had hoped.
Historically, the North American iron powder shipments mirrored the automotive industry, with over 70% of the iron powder shipped used for parts in internal combustion engine (ICE) automobiles and light trucks. As you can imagine, the alarm has been sounded regarding the move to alternative fuel systems and subsequent elimination of ICE.
How much PM is in a North American automobile? A single, all-inclusive weight estimation is difficult, as there are numerous variables, such as the platform: pickup, large SUV, crossover, sedan; the make and design: North American, Asian, or European; engine type: ICE, hybrid electric (HV), electric (EV); or drivetrain: all-wheel, front-wheel, rear-wheel, or 4-wheel.
In 2020, light truck production hit a record high of almost 80% of all vehicles produced in North America. This is fantastic news for the PM industry as light trucks (pickup/large SUV) account for an estimated average of 27.2 kg (60 lb) of PM per vehicle, followed by mid-size/crossover at 18.1 kg (40 lb), and sedans at 9.1 kg (20 lb). HV and EV are difficult to estimate. Powder-forged connecting rods and PM main bearing caps are not readily used in HV. EV estimates range from 1.8-3.6 kg (4-8 lb) of PM.
Based on robust light truck sales and the small penetration of HV and EV, the estimated average weight in a 2020 North American passenger vehicle was 16.8 kg (37 lb), a decline of 5.1% from 2019. Many industry experts project the PM weight in passenger vehicles will decrease 1–2% annually without new applications, a greater acceptance of powder-forged connecting rods and PM main bearing caps in HV, and the result of fewer parts in an EV.
Several PM parts makers report that the future for PM will be to supply value-added, near-net- shape parts that have cost-effective lean-alloy materials with high material utilization rates. To help accomplish this, powder producers are improving and developing new materials that exhibit higher green strength, excellent machinability, increased compressibility, and have their sights on increasing the development and use of soft magnetic composites (SMC). SMC materials have an integral role in the future of electric vehicles, as well as home appliances and other electric devices. Advances in magnetic modeling are allowing engineers to create more efficient designs with the 3-dimensional manufacturing capabilities of SMC materials, that are not constrained by 2-dimensional construction limitations of laminated steel. SMC materials operate at very high frequencies without hysteresis and eddy current losses, another advantage over their laminated steel counterparts.
The Internet of Things, or Industry 4.0, has made its presence known in the PM industry. Augmented intelligence continues to assist and optimize the manufacturing processes through sensors that learn the process and adjust based on data trends. COVID-19 workforce reductions affected many companies’ ability to efficiently operate equipment, increasing the demand for automation. From pick-and-place robots at the compacting presses and furnaces to 100% vision system inspections, automation continues to increase.
Compaction presses continue to evolve with sophisticated motion controls, resulting in precise movement of tools with faster cycle times. Fully integrated electric compaction presses are increasing the productivity for tungsten carbide and ceramic high precision cutting tool inserts. Furnace manufacturers also see the future of SMCs. New approaches to lubricant removal and the ability to cure parts in one continuous cycle will reduce manufacturing costs and increase throughput, while improving handling and quality.
Metal injection molding and additive manufacturing
While general manufacturing was down in 2020, metal injection molding (MIM) and metal additive manufacturing (AM) performed much better. Domestic and globally produced MIM and AM fine powders (less than 20 micrometres) consumed in North America increased an estimated 3-5% to 3,741-3,809 mt (4,125-4,200 st). Low-alloy and stainless-steel made up the bulk of the powders consumed.
Improving powder quality, most recently driven by AM, including a narrower particle size distribution range, greater sphericity, fewer satellites, and less internal porosity, will improve throughput, mechanical properties, and overall process consistency. Typically, these powders are manufactured by gas atomization, but capacity has been added recently for plasma atomization and research continues to develop water-atomized low-alloy materials for MIM and AM.
Industry sources don’t see radical changes on the horizon for injection molding machines, other than applying Internet of Things utilities and augmented intelligence to reduce labor while increasing productivity. AM build machines continue to evolve. Office-friendly small units to production scale are being released monthly. Multi-laser units continue to increase speed, build size, consistency, and robust properties for performance parts. Bi-directional single-pass binder-jet units are resulting in speeds up to 100 times faster than other metal AM platforms.
There continues to be a need for additional thermal treatment equipment for MIM and AM. MIM and AM binder-jet processes require de-binding prior to sintering, and most direct laser sintering process require stress relieving after printing. Research activities continue to provide new insight into identifying ideal temperature and atmosphere conditions for more efficient energy utilization and process optimization.
It is safe to say that the partition between MIM and AM processes is disappearing. At least a dozen MIM companies have added in-house AM capabilities or are collaborating with others, bringing parts to market quicker, using the same powders, without the need for tooling. When quantity levels justify, the parts can be moved to MIM.
The refractory metals market in 2020 was down significantly for both North American Powder Shipments as well as for imports. Compared with 2019, North American powder shipments of tungsten carbide powders in 2020 were down an estimated 34.6%, and imports of tungsten carbide powders were down by 41%, both of which truly indicate the significant impact that COVID-19 has had on the refractory market.
The tungsten market was estimated slightly down overall, but strong growth in the semiconductor chip industry drove demand for high purity tungsten powder. 5G networks, smartphones, computers, vehicles, and other Internet of Things devices require pure tungsten. Additionally, tungsten powder required for defense remained strong. Traditional uses for tungsten powders were significantly depressed.
The tungsten carbide markets continued to slide in 2020 due to the devastated oil and gas market; decreased US and global coal mining; and a decrease in demand for tungsten carbide cutting tools due to a reduction in manufacturing. Aerospace and automotive had a real impact in reducing the demand for cutting tools. The immediate drop in aerospace demand led to order cancellations and production stoppages.
North American oil and gas rig counts finished the year at the lowest levels since recordkeeping started in 1949. At the end of 2020, the NA rig count was 410 compared to a 20-year average of 1,505 and the most recent five-year average of 805. In 2020, coal mining in the US was down 24% and coal consumption was down 19% according to the US Energy Information Agency.
Molybdenum powder shipments for 2020 was estimated down 15.4% compared with 2019. In 2020, North American molybdenum powder demand was estimated to be down by 40–45%. Depressed markets negatively impacting molybdenum demand included aerospace, automotive, and certain structural components.
Advancing powder metallurgy
The MPIF Technical Board continues to keep a keen eye on lean alloys, advanced PM steels, SMC, and lightweight materials. The Technical Board is also studying processing variables and their influences on variation in material properties and dimensional stability in PM parts. The latter review concerns how materials react to heat treatment and compacting with the goal of achieving closer tolerances and reducing the need for extensive machining. Additionally, during 2021, the Technical Board will assess and update the PM Industry Roadmap, most recently revised in 2017, to ensure that our industry has identified the technology challenges to remain the preferred metal-forming solution.
The Center for Powder Metallurgy Technology (CPMT) continues to work on numerous projects. Ongoing investigations include corrosion prevention, impact testing of gear teeth, joining PM components, variation reduction in the PM process and fatigue testing. The variation reduction investigation is a collaboration with the MPIF Technical Board, and the fatigue study is in coordination with the MPIF Standards Committee, resulting in new data for the MPIF Standard 35-SP.
MPIF, CPMT, and the National Science Foundation (NSF) have been champions of advancing the PM technology through educational outreach. Over the past 4 years, over 200 engineering students have been awarded conference grants through the efforts of these organizations. The grants provide the opportunity for the PM industry to showcase the technology to some of the brightest young minds that will someday, hopefully, select PM as their metal-working solution.
MPIF, the European Powder Metallurgy Association (EPMA), and the Asian Powder Metallurgy Association (APMA) have continued collaborating to advance the technology through the Global Powder Metallurgy Materials Property Database. Launched back in 2004, the updated database is easier to navigate, download data, and best of all, it puts materials property data into the hands of the parts designers for free.
Powder metallurgy outlook
The writing is on the wall. Whether we like it or not, the automotive industry will change due to ambitious efforts to curb the production of ICE propelled vehicles by 2035, and the trickledown effect will affect the entire PM industry. I believe the industry will be able to adapt and overcome, but we will need the mindset and resources to adjust to the changing environment.
There are unlimited opportunities for metal powders. Some of the most interesting research relates to sustainable solutions for our planet. One of the ongoing energy projects uses iron powder as an energy source. When iron powder is combusted with hot gases to drive an engine, the result is rust. The oxygen is extracted from the rust particles using hydrogen produced from sustainable electricity surpluses to turn it into iron powder again, and the process repeats.
Another energy-focused project is a new infrastructure for storing zero-emission metal-hydride energy. This innovative, safe, and compact all-in-one renewable energy storage solution utilizes a metal alloy powder from hydrides. High-density PM pellets of the alloy are an efficient solid- state storage material for hydrogen gas, resulting in smaller tanks, operating at lower pressure and temperature, helping drive the global energy transition.
Other non-traditional applications for metal powers include water purification. Not only is this of great benefit to community water sources, but it is also a humanitarian effort for developing countries that need to remove multiple contaminants from groundwater and drinking water in a single step.
These are just a few examples of new opportunities for metal powders. Through cooperative efforts, we will improve the technology, opening new opportunities to demonstrate PM’s problem-solving advantages – now and in the future.
The future is bright for the PM industry, but we need to be looking years down the road, even decades, rather than months. There will be bumps in the road along the way that impact the industry, such as recent computer chip shortages, downturns in oil drilling, and the evolving automotive industry, but they should not define us. Now is the time to identify who we are as an industry. We need to invest in research and development to create new applications using metal powders and PM parts, and showcase the attributes of this exciting technology.
This story uses material from the MPIF, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.