The space industry is quickly growing, it is predicted that by 2040 it will be worth over a trillion dollars. Keith Ferguson, Senior Businees Development Manager at Morgan Advanced Materials’ Braze Alloys Business, describes how braze alloys play their part in sustainable, safe, and reliable space exploration.
The phrase made famous by Neil Armstrong, “one small step for man, one giant leap for mankind,” is the perfect advertisement for space exploration and its importance to the future. Space exploration has developed quickly since 1957 when the first artificial satellite, Sputnik 1, was propelled into space. Since then, the world has witnessed marvels such as the launch of the International Space Station, the 1970s space shuttle programme, and landing on the moon.
The importance of these missions is immeasurable, whilst most of us may not realize on a day-to-day basis, space exploration has improved lives and also the global economy, massively. Places these benefits are seen include predicting natural disasters, forecasting sea level patterns, broadcasting TV and radio, simple weather forecasting, monitoring for fertile land, and even helping research in muscular atrophy.
Due to all of these benefits this space industry has massive value. In 2017, it was reportedly worth $384 million USD, rising at a rate of 7.4%. By 2040, Morgan Stanley sees the industry growing to be worth $1.1 trillion USD.
Yet, there are challenges. Many people think that the millions of dollars and resources used to explore space could be put to better use on immediate threats to society like famine, poverty, or clean water, to name a few. There are internal operational challenges outside of external opinion, namely, space exploration must become more sustainable and safer. Brazing alloys are a big part of solving these challenges.
A Brief History on Brazing in Space
Put simply, brazing is the process of joining two metals by heating and melting a filler (alloy) which bonds to the two pieces of metal and joins them together. The filler is required to possess a melting temperature which is less than that of the metal pieces.
The utilization of braze alloys in space equipment is critical to the mission. This is because they permit sensors to be mounted as near as possible to engines to calculate and observe output and feed data back to operators. They have already aided missions which were successful. Two of Morgan Advanced Materials’ braze alloys, RI-46 and RI-49, were specifically engineered and employed by NASA on the Space Shuttle Main Engine, also known as the RS25.
RI-46 was specifically developed as a substitute for the existing Nioro braze alloy, which is made up of 82/18 Au/Ni (gold/nickel). RI-46 is comprised of much less gold, adding in manganese and copper instead. This provided important weight savings as it helped to make the braze alloy much less dense, but also still operable in a wide scope of temperatures, between -240 °C to 700 °C (-400 °F to 1292 °F).
These alloys have not only been crucial for space missions in the past, but also for future missions. RI-46 and RI-49 have been employed for NASA’s Space Launch System (SLS), a vehicle that is planned to take a crewed mission to Mars. Developing new braze alloys is as much about performance as it is sustainability.
The Requirement for Non-Precious Alloys
It is obvious that space exploration is costly. The average cost to launch a Space Shuttle is $450 million per mission according to NASA. The orbiter which was built to replace the Space Shuttle Challenger, the Space Shuttle Endeavour, cost a massive $1.7 billion USD.
To keep space missions possible, lowering costs is clearly needed. Decreasing the utilization of precious metal braze alloys is one crucial element of cost reduction. Precious metals such as palladium and gold are becoming more and more scarce. Therefore, the cost of creating alloys from these precious metals is also increasing.
Yet, there can be a reluctance to stop using precious metal alloys. Many years of research, development and data means these alloys are reliable and tested. When planning missions and equipment that cost hundreds of millions of dollars and, more importantly, the lives of crew members, reliability becomes a key point, and failures have to be prevented.
Morgan’s Braze Alloys business has been researching and developing non-precious metal alloys over a number of years in order to solve this issue. These solutions are just as strong as their equivalent high precious-metal counterparts, but at a fraction of the cost, as observed from the RI-46 and RI-49 alloys.
Non-precious metal alloys can be manufactured using metals such as chromium, nickel, and cobalt. In the aerospace sector, their success has already been seen, and now research is being pioneered into making them fit for space.
Space, For All to Enjoy
Space travel is not only for public benefit and highly trained astronauts, there is also an increasing commercial aspect. Radio and satellite TV have been discussed already, but billionaire entrepreneurs such as Elon Musk and Richard Branson have also been pioneering private space travel. The aspiration is that civilians may also be able to enjoy outer space as well one day, though for potentially high prices.
Fulfilling this dream is dependent on safety and reliability because lives will be at stake. The ability to place sensors as near as possible to the spacecraft’s engine is the key to improving these factors.
By allowing sensors to be located as near as possible to the spacecraft’s engine, crew and mission control can accurately read and measure data and output. This includes temperature, gas flow, fuel efficiency, and observation for fire detection or abnormalities. Data readings become unreliable and missions can be compromised if these sensors are located too far away from the engines.
Recent news has shown why sensor technologies are crucial, after a post-rocket launch failure a two-man space crew had to abort their flight to the ISS. The Soyuz spacecraft began to experience failure 119 seconds into the flight, and it is reported that problems were noticed by the crew first, not mission control.
The crew explained feelings of weightlessness, which is a sign of an issue during that stage of the flight. Luckily, they aborted, ejected their capsule from the rocket, and returned safely to Earth.
At the time of writing the cause of the failure is still to be identified, but clearly a situation such as this should not be happening. Any problems should be picked up by mission control, and not be reliant on crew judgment. The challenge though, due to the requirement to resist corrosion and high temperatures, usually up to 950 °C (1742 °F), is that some sensors are made from ceramic. Yet, these ceramic sensors must then be joined to metallic parts of the engine.
This is where ‘active alloys’ can be used. These alloys can join metal to ceramic, or even ceramic to ceramic – unlike regular braze alloys that join metal to metal. Industry standard active alloys such as Ticusil® and Incusil®-ABA from Morgan’s range, are still in use today but were developed up to 40 years ago. New alloys are currently in development to tolerate much higher temperatures.
A Never-Ending Journey
There is still so much to learn and explore about space, and the same can be said for Morgan’s journey with braze alloys. Morgan Advanced Materials is not just committed to making the space industry safer and more sustainable, but it is aiding applications across all industries. A key pillar of this is through Morgan’s highly specialized Metals and Joining Centre of Excellence (CoE), based in Hayward, California, in addition to Morgan’s Brazing Department.
Morgan Metals and Joining CoE, Hayward California
With highly trained scientists and researchers, Morgan’s Braze Alloys business can create bespoke alloys for specific applications, run trials to test materials, braze cycles and fixturing. The whole operation can be looked after from beginning to end, from powder atomization, to preform fabrication and brazing trials.
Flexicore® is one of the latest developments being pioneered at the Metals and Joining CoE. This new technology changes traditionally brittle alloys (for example AMS4777) into a flexible wire form.
Wire Form Braze Alloys
When it comes to repeatability and ease of use this will be far superior to pastes for the vast majority of cases. In addition to the operational benefits, Flexicore® will also enable the utilization of nickel-based alloys to replace precious-metal alloys. This will also help to lower costs for operators and manufacturers.
Watch this Space
Richard Branson predicts that for his own Virgin Galactic programme, space travel is only two or three flights away. We are not far away from entering a new world, and brazing alloys will influence how the space industry turns out.
Morgan’s Braze Alloy solutions, such as RI-46 and RI-49, in addition to others like Palniro-1 and Palniro-7, can already be seen across the numerous spacecraft and programmes. Through further research and development, who knows where this important industry could lead.
This information has been sourced, reviewed and adapted from materials provided by Morgan Advanced Materials - Braze Alloys.
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