Get talking: Changing the way we manufacture

Materials World magazine
,
1 Aug 2018

As we progress from a society of mass production to mass customisation, additive manufacturing is contributing greatly to this trend. Haim Levi, VP Manufacturing and Defence markets at solution provider XJet, looks at why this technology is gaining traction in technical ceramics.

Additive manufacturing (AM) has been trailblazing since its inception a few decades ago. Continually improving in quality, build size, material choice and applications, plastic and metal 3D printing have been slashing time-to-market and production costs in the automotive, aerospace, healthcare, dental, electronics, and machinery industries for years. 

The technology has evolved from predominantly producing prototypes to manufacturing end-use parts that improve products by reducing weight, production times, tooling costs, or delivering complex geometries. Adoption of the technology in technical ceramics is still in its infancy but has experienced a surge following implementation by several users for some promising applications. 

Rising market potential

Ceramics additive manufacturing is a young specialty that emerged from the more mature plastics and metal AM sectors, which have been around for several decades. This fresh discipline focuses on real parts for end user applications and is receiving growing levels of acceptance from leading manufacturers. It also shows impressive potential, as evidenced by a compound annual growth rate (CAGR) of 21.4% from 2015 to 2017, according to the 3D Printed Technical Ceramics: Technologies and Global Markets Report, published by BBC Research. Experts predict that the global market for 3D printing of technical ceramics will rise from US$174m in 2017 to US$544m in 2022, and could be worth US$3.1bln by 2027, according to figures from the Market Report: the US$3.1bln Market for Ceramics Additive Manufacturing, Smartech Markets Publishing. 

Technical ceramics AM will complement and, in certain cases, replace traditional manufacturing methods such as ceramic injection molding, hot isostatic pressing (HIP), and various casting methods, especially when facing short to medium runs of complex parts. This will provide huge savings in time and cost, while retaining part performance.  

Technical ceramics, also known as engineering, industrial or advanced ceramics are used in a vast number of industries today due to their extraordinary properties such as high-temperature resistance, toughness, strength, chemical resistance, abrasion resistance and more. For certain applications, ceramics surpass metal capabilities and are in growing demand in leading industries.    

Additive manufacturing today

Parts are produced using several traditional methods, including injection molding, HIP, extrusion, and casting. All require tools, which can be expensive – particularly when calculating cost per part for short runs. AM has proven to be a valuable replacement of traditional manufacturing methods by eliminating the tooling process, resulting in significant time and cost savings. 

Also, as an additive process, huge benefits are gained in design freedom. In a subtractive manufacturing process, access to internal cavities of parts can be restricted, limiting tool paths. Conversely, with additive manufacturing complex geometries are as easy to produce as simple parts.

Furthermore, it allows multiple parts to be built simultaneously on the same build tray. This could include different design iterations, different size options, parts for an assembly, or a repeated control part for functional testing. All available within a matter of hours – and all manufacturers need is an additive manufacturing system and a digital file. 

In addition, ceramics AM will enable a new range of applications and uses that were not possible before, such as conformal cooling channels in mould inserts, personalised implants and other medical supporting devices, as well as creating complex geometries that will reduce part weight while optimising strength.

Part properties 

Ceramic AM parts achieve physical properties equal to traditionally made parts. Geometric properties, however, can change according to the manufacturing technology used and may require finishing, potentially adding time and cost to the process. In this regard, nanoparticle jetting (NPJ) technology delivers a breakthrough advantage with its ability to reach Near Net Shape of parts. The accuracy afforded by NPJ technology produces parts with excellent shape and dimensional tolerance meaning less machining is required in the green stages, further reducing costs and timescales. 

This new technology, different from other AM processes such as stereolithography, digital light processing, and binder jetting, delivers high quality ceramic parts with smooth surfaces, superfine details, high density, and excellent dimensional tolerance. This is achieved using the dispersion of nano-sized ceramic particles which are suspended in a liquid formula and jetted from inkjet nozzles building very thin layers. The various shapes and sizes of these nanoparticles allow for natural packing and high density, resulting in strong, tough, and hard parts. The liquid ceramic dispersion is contained in enclosed cartridges, offering safe and easy-to-use material handling.

A transformation is taking place

The potential of AM in technical ceramics is vast. The readiness of the technology, the size of the potential market, the variety of applications, and the advantages afforded to users all point to a transformation in the industry. The healthcare, energy and automotive industries that adopted plastic and metal additive manufacturing are now starting an exciting journey into technical ceramics. The technology is expected to gain full acceptance as a valid, needed, and even preferred manufacturing method. In terms of potential, ceramic additive manufacturing seems to be heading for a brilliant future