Which country has recently developed the world’s first 3D-printed jet engine?

Australia
Australian researchers have created world’s first 3D jet engines using 3D printing. The technology is believed lead to cheaper, lighter and more fuel-efficient jets. 3D printing makes products by layering material until a three-dimensional object is created. Automotive and aerospace companies use it for producing prototypes as well as creating specialized tools, mouldings and some end-use parts.