Spinal joint replacement patients could potentially receive individualised, metal 3D-printed implants, thanks to research partnership Metalysis and TWI.
A project from the two companies has shown the feasibility of using tantalum powder in metal additive layer manufacturing for biomedical applications, such as patient-bespoke spinal implants.
Both uniform and randomised bio-inert titanium lattice structures were produced in the study, replicating the structural stiffness of bone. The structures are designed to allow for extensive integration with bone cells to promote acceptance by the body.
Metalysis has developed a process that produces metal powders directly from their respective oxides in one step, drastically lowering the environmental impact of its manufacture. According to a press release, this process is cost-competitive, and produces perfectly spherical metal powders of uniform size. When used in metal additive manufacturing, the end product should thus be structurally consistent, allowing for an improvement on the as-built surface finish. The study has shown that the properties (i.e. durability and inertness) of this highly metal are retained through the production process. This is apparently facilitated by the quality of Metalysis’ powders, which allow the 3D printer to lay down the metal, forming a lattice structure, with consistent strength and density.
According to Metalysis, most additive manufacturing technologies to date have focused on the use of commodity plastics because powdered metals, until now, have proved too expensive to be widely used for this process. Now, Metalysis’ high-quality metal powder, combined with TWI’s expertise, has demonstrated the significant potential of creating lattice structures using a specific metal additive manufacturing technique—selective laser melting (SLM) – for use in hip joints, implants and other new biomedical products that will both benefit patient wellbeing and bring cost savings to the wider market, according to a press release. Research specialist TWI has a history of bringing advances to the medical industry, and this study shows that Metalysis’ metals can be used to manufacture prototypes of the highest levels of quality, by exploiting SLM additive manufacturing technology.
Metalysis produces high-quality metals, including tantalum and titanium. Its patented process is intended to replace the expensive and highly toxic Kroll or Hunter processes which have been used for the past 70 years. Up until now, the inefficiency and expense of this process has made titanium and tantalum prohibitively expensive, according to a press release. Since the launch of its commercial plant in 2015, Metalysis has been supplying tantalum powder to its clients globally, working in collaboration with LPW Technology to serve its additive manufacturing customers.
Richard Pargeter, a technology fellow at TWI, comments: “We have already seen the great success Metalysis has had printing automotive parts. Our analysis suggests these metals are incredibly versatile and highly suited to the medical industry…allowing patients to have a tailor-made joint…rather than being restricted to the choice of standard sizes now available.”
Dion Vaughan, chief executive of Metalysis, says, “TWI has great expertise, particularly in the use of lasers in additive manufacturing, which we hope will help to bring individual joint replacements into the mainstream of mass manufacture.”