Public Funding for C4 Carbides Limited

The REALM project will develop a new, sustainable manufacturing technology to produce hard-facings for downhole drilling tools. The proprietary technology uses a novel metal additive manufacturing process based on Directed Energy Deposition (DED) to form highly wear resistant hard-facing coatings in-situ, using elemental powders. The super-hard coating is characterised by a strong metallurgical bond showing a continuous metal-matrix and finely-dispersed carbide precipitates creating functional graded microstructure necessary for wear and erosion applications. This has overcome the drawback encountered when using commercial hard-facing tungsten carbide powders. The project is expected to deliver three innovations: 1. Automated, low-heat input manufacturing process to form functionally-graded hard-facings; high toughness at the coating-substrate interface and high hardness on the surface. 2. Reactive powder composition formulated using a wide variety of application-targeted material combinations. 3. Design freedom of hard-facings to optimise coating geometries for improved heat dissipation and performance. The innovative DED process will benefit the environment; the near-net shape process will lead to more efficient application of tungsten and cobalt thus minimising waste of these expensive at-risk commodities. Localised heating using a laser beam will save energy and greenhouse gases. In service, the downhole tool will exhibit higher performance and will lower energy consumption, whilst its higher longevity will reduce the demand for the primary production of "at-risk" metals.

To create a new carbide composition for metal additive manufacturing processes and technologies for linear edge saw blades.

"C4 Carbides innovative saw blade development program will use Selective Laser Melting (SLM), a metal Additive Manufacturing (AM) technology, to fuse super-abrasive powder to form tooling grade hard materials into net shape 'sharp' cutting teeth, eliminating the needs of post process grinding. UK patents for this concept have been filed. Compared to conventional tungsten carbide tipped (TCT) saw blades, the AM process create high performance cutting teeth for specialist applications tailored to customer specifications. The digital manufacturing process enable C4 meeting challenging design changes and fast respond to customer's requirements. SLM allows material saving of 70-80% and energy and production savings of over 50%, as compared to conventional TCT blade manufacturing. To ensure the success of the AM tooth formation innovation, four key elements are crucial: 1. Identifying and developing the use of high performance super-hard materials by SLM. 2. New optimised tooth designs for additive manufacturing. 3. Process innovation in aligning and precisely forming super-hard teeth on continuous preformed strip. 4. Technology scale up for serial production. A new range of cutting tool geometries can be offered, and specific customer requirements for new materials and designs can be made the same day. We aim to transform the linear edge market within 5 years of successful completion of this project."

"We will use innovative additive manufacturing to radically update the process for forming hard teeth on saw blades. The most commonly used tooth tip material is tungsten carbide. In a typical tipped blade less than 1% of the high value wear material is used. The rest is machined off during the manufacturing process or left on the base and discarded when the sharp edges are worn. State-of-the-art tungsten carbide tipped (TCT) teeth are currently formed by welding pre-formed tungsten carbide inserts to steel strip and then grinding these to a sharp edge. The need to manipulate individual inserts means that fine-toothed metal-cutting blades ( \>6 Teeth Per Inch) cannot currently be manufactured. The grinding process is environmentally wasteful - of materials, energy and coolant. Our new process uses micro laser metal deposition (micro-LMD) of the tip material to form the hard cutting edge, thus avoiding the need to manipulate and weld TCT inserts. In LMD, a jet of powder (eg tungsten carbide) is directed at a surface while being simultaneously melted into the surface by a focused laser beam. We have obtained two patents on tooth-making via LMD. With our subcontractor ManuDirect we have experimented with micro-LMD in a test rig and have been able to achieve hard surfaces on teeth and proved their ability to cut. The edges of these teeth are still rounded; we are not yet able to form a sharp 'zero radius' cutting edge. However, once we are able to do so, we will have created a near-net-shape tooth, reducing or eliminating the need for subsequent grinding, or even permitting laser sharpening. Our process should also be applicable to all types of blade and other metal-ceramic combination. However as tungsten carbide is the most widely used abrasive it is our initial focus. The greatest opportunity will be in fine-toothed metal-cutting blades ( \>6 TPI) where there is currently no possibility of using TCT inserts and conventional bimetal blades blunt easily. In addition, we see an opportunity for a wood cutting saw blade that sits in the gap between bimetal and TCT in terms of cost and performance. The lead partner is a manufacturer and exporter of abrasive saw blades and will exploit the process through its customer base. The consortium includes a powder supplier, the UK's leading university in this area and a subcontractor that is expert in micro-LMD equipment."

C4 Carbides currently manufactures linear edge tunsten carbide and diamond coated strip for cutting and drilling products. Tungsten is high on the list of ‘at risk’ minerals so there is an incentive to substitute tungsten carbide by other minerals. Diamond is a good alternative in many applications but is not suitable for ferrous materials. Cubic Boron Nitride (cBN) is an alternatve - but the technologies to braze cBN on to flexible strip are not yet developed. The purpose of this project is to develop the coating and braising technologies to enable cBN to be applied to strip for many ferrous cutting and drilling tasks. If the project objectives are achieved, C4 will be able to offer a range of linear edge superabrasives to the estimated $2bn linear edge market. The resulting products should last up to 20 times longer than tungsten, bi-metal or carbon steel blades and C4 will be in a position to pioneer the complete removal of tungsten from linear edge blades.

The project concerns new coatings for the cutting tools used in many advanced and high-value manufacturing applications. It will explore systematically the possibility of simultaneously (i) substituting diamond grit for tungsten carbide using a novel coating technology and (ii) retooling worn out tools and cutting blades rather than disposing of them. In parallel the project will explore the feasibility of innovative business models that that are both more sustainable - which enable the substitution and/or remanufacturing to take place - and deliver superior value systems. One possible model might involve charging for the use of a cutting tool in key high performance applications rather than the blade itself.

C4 Carbides currently manufactures and sells three product ranges: synthetic diamond-coated & tungsten carbide-coated power drill accessories and tungsten carbide saw blades. These are sold to some of the world’s leading brands including Bosch, Black and Decker, AEG and Hitachi. We have developed a novel method for diamond coating. This project aims to combine our diamond-coating process, the continuous strip line process and a patented reduced kerf design to develop a range of diamond band-saw blades. There are technical challenges involved in making the blades because the diamonds must be bonded to the steel in a way that maximises the cutting and abrasion performance whilst retaining (or even improving) the flexibility and fatigue resistance of the backing material. Normally, diamond grit is either sintered (embedded in a powder and heated) or electroplated onto the substrate. The C4 process involves coating the diamond grit with a special ceramic layer, and then brazing the coated diamonds onto the substrate without using a vacuum. The ceramic layer is capable of forming a bond with the metal carrier during the brazing process. This innovation has led to performance improvements and lower costs and the C4 diamond-coated product range has generated significant new sales, principally in rigid hole saw blades and drills. The band saw blades will be optimised for particular applications and tested with potential customers. We will address two distinct market segments, each of which has particular technical requirements. A proof of market study has previously identified that the cutting of graphite is the largest and most technically achievable application. Of the other potential applications we currently target the silicon wafer slicing market that we believe has high value and massive growth potential driven by demand from manufacturers of semiconductors and photovoltaic panels.

To develop a capability in new diamond-to-steel bonding processes to enable expansion of linear edge technology into new products and markets.