In the United States, steelmaker Cleveland-Cliffs announced in May the indefinite closure of its Conshohocken plate finishing facility in Pennsylvania – a plant that has provided specialised armour plating for US Navy ships, army ground vehicles and thousands of mine-resistant military vehicles for decades.
Armour steel is a core material for national defence, military industries and special equipment. It possesses extreme properties such as ultra-high strength, hardness, toughness and low thermal conductivity.
Its production has been difficult, expensive and inefficient. Project leader Duan Aiping told the newspaper that to overcome these challenges the research team had upgraded their cutting tools with an ultra-hard material and reduced production temperatures so that the tools lasted longer.
Duan said the new cutting tools were made from cubic boron nitride, a synthetic material that is almost as hard as diamond – the hardest naturally occurring mineral.
