"Rare earth high-iron aluminum alloy" in troubled waters

According to relevant research reports, in the next five to ten years, China will usher in the rapid development of aluminum alloy cables, even if the use level of China's aluminum alloy cables only reaches the current international general level (30%), it will quickly form a huge market
of up to 300 billion yuan.
It can be said that China's cable market can be described as a real blue ocean
.

With the rise of domestic aluminum alloy cables, some manufacturers began to focus on promoting an aluminum alloy cable called rare earth high-speed rail, and claimed that the aluminum alloy conductor treated by rare earth has greatly improved its performance in many properties such as conductivity, flexibility, creep resistance compared with pure aluminum, and some even claim that many properties are better than copper conductors, giving people the illusion
that rare earth treatment can make a qualitative leap in aluminum performance 。 In this regard, Chen Kun, director of the China Wire and Cable Standards Committee, directly gave this evaluation in the face of the media: "Many domestic enterprises are actually following the trend, indiscriminately creating concepts, such as high-iron aluminum alloy, rare earth high-iron aluminum alloy, etc.
, all kinds of publicity, making people confused, which is a common method
in the irrational and disorderly competition in China's cable industry.
" ”

Rare earth high-iron aluminum alloy cables, which are referred to by the industry as "random concepts", have been trying to blend into the mainstream market in recent years and compete
with real aluminum alloy cables.
The reason is nothing more than that the aluminum alloy cable has only entered the Chinese market for six or seven years, and most of the domestic aluminum alloy cable companies have a shallow understanding of aluminum alloy cable, and most of the technology and production level are in the early stage, which urgently needs to be guided and standardized, so that the concept speculators have an opportunity
.

As early as 30 years ago, Huang Chongqi, an expert in pressure processing of non-ferrous metals and their alloys and academician of the Chinese Academy of Engineering, led the Shanghai Electric Cable Research Institute to research and develop rare earth aluminum alloys and successfully obtained national invention patents, which also became the early exploration
of aluminum alloy cables in China's cable industry.
Subsequently, around 2010, with the gradual launch of the domestic aluminum alloy cable market, many companies began to choose to "borrow" from the scientific research achievements
of Academician Huang.
As everyone knows, as the inventor of rare earth optimization treatment technology, Academician Huang has clearly pointed out in the paper "Application of Rare Earth Optimization Treatment in the Production of Electrical and Aluminum Conductors" published as early as 1985 that it is better
to use aluminum containing silicon 0.
09%-0.
13% for the application of rare earth optimization treatment.
For low-silicon aluminum ingots, as long as they are aluminum ingots with a silicon content of no more than 0.
08%, under the premise of ensuring good processing technology, there is no need for rare earth treatment
.
In June this year, when attending the "Aluminum Alloy Wire for Cable Conductor" (GB/T 30552-2014) and "Rated Voltage 0.
6/1kV Aluminum Alloy Conductor Cross-linked Polyethylene Insulated Cable" (NB/T 42051-2015) Publicity and Technical Seminar" held in Shanghai, Academician Huang Chongqi also said in a clear position: "The hype of rare earth high-iron aluminum alloy is completely false proposition, and manufacturing enterprises should be responsible for product quality!"

The industry authority Shanghai Electric Cable Research Institute in the "Cable Aluminum Alloy Conductor and Its Performance Research" has already clearly pointed out through relevant experiments that the performance of aluminum alloys that are not added rare earths will be improved, depending on the specific situation (silicon content
).
In the production of aluminum and aluminum alloys with aluminum ingot with a purity of 99.
7% and a silicon content of about 0.
04%, the addition of rare earths has little effect
.
With the development of silicon removal technology, at present, aluminum ingots with aluminum purity of 99.
7% and silicon content of about 0.
04% have been widely used in China to produce aluminum rods, which is equivalent to directly declaring that adding rare earths to qualified aluminum materials is actually meaningless
.

On the other hand, the so-called rare earth high-iron aluminum alloy in China contains both high iron elements and rare earth elements
.
As mentioned earlier, the optimization of rare earths is also related to other elements in aluminum, especially iron, this effect is more obvious when the iron content is relatively low than when the iron content is high, and the high iron content weakens the optimization of rare earths, if the higher iron content and the optimization treatment of rare earths on the overall electromechanical performance of aluminum or aluminum alloy rods are actually contradictory
.

Only when an enterprise uses poor purity aluminum materials as the base material of conductor aluminum alloy, it may consider adding rare earths to make up for the lack of material performance, and this aluminum alloy cable itself has certain performance problems, so there is no so-called "rare earth high-iron aluminum alloy cable"
with more performance advantages.
At the same time, in the preparation instructions of the industry standard "rated voltage 0.
6/1kV aluminum alloy conductor cross-linked polyethylene insulated cable" NB/T 42051-205, which will be officially landed on September 2, the statement of rare earth high-iron aluminum alloy is also directly given a clear negation
.
Up to now, there are no sufficient application cases in China to prove the service life and long-term safety and reliability
of rare earth high-iron aluminum alloy cables.

Rare earth optimization treatment technology is essentially an optimization for high silicon non-electrical grade aluminum ingots, reducing the harmful effect of silicon on conductivity, and can not bring a qualitative change in performance to aluminum or aluminum alloy, and this optimization is closely related to the size of iron content, the higher the iron content, the less obvious its optimization effect, the promotion of
rare earth high-iron aluminum alloy cable is contradictory.
In the current industry background of low silicon aluminum ingot application, the application of this optimization technology is no longer necessary, and rare earths, as a national strategic resource, should be applied to where they are needed as much as possible, rather than as a publicity gimmick, resulting in blind use and unnecessary waste
.