The invention relates to a method for preparing amorphous particle-modified magnesium alloy surface-gradient composites and pertains to the technical field of composites. The method comprises steps of: holding the temperature at 150˜350° C. for FeCrMoBC amorphous alloy particles; mixing pure magnesium, pure zinc, pure aluminum, pure copper and Mg-5 wt % Mn alloy under continuous protective gases, gradually raising temperature to 720˜760° C. and melting at a constant temperature for 15˜25 min to obtain a magnesium alloy melt; cooling the magnesium alloy melt to 600˜635° C. and starting mechanical stirring; continuing the cooling until the semi-solid temperature is 570˜615° C., slowly adding the above FeCrMoBC amorphous alloy particles, holding for 2˜5 min after mixing evenly, and cooling the crucible with water to obtain an amorphous particle-modified magnesium alloy surface-gradient composite.

A metal powder for additive manufacturing having a composition including the following elements, expressed in content by weight: 0.01%≤C≤0.2%, 2.5%≤Ti≤10%, (0.45×Ti)−1.35%≤B≤(0.45×Ti)+0.70%, S≤0.03%, P≤0.04%, N≤0.05%, O≤0.05% and optionally containing: Si≤1.5%, Mn≤3%, Al≤1.5%, Ni≤1%, Mo≤1%, Cr≤3%, Cu≤1%, Nb≤0.1%, V≤0.5% and including eutectic precipitates of TiB.sub.2 and optionally of Fe.sub.2B, the balance being Fe and unavoidable impurities resulting from the elaboration, the metal powder having a mean roundness of at least 0.70. The invention also relates to its manufacturing method by argon atomization.

A metal powder for additive manufacturing having a composition including the following elements, expressed in content by weight: 0.01%≤C≤0.2%, 2.5%≤Ti≤10%, (0.45×Ti)−1.35%≤B≤(0.45×Ti)+0.70%, S≤0.03%, P≤0.04%, N≤0.05%, O≤0.05% and optionally containing: Si≤1.5%, Mn≤3%, Al≤1.5%, Ni≤1%, Mo≤1%, Cr≤3%, Cu≤1%, Nb≤0.1%, V≤0.5% and including eutectic precipitates of TiB.sub.2 and optionally of Fe.sub.2B, the balance being Fe and unavoidable impurities resulting from the elaboration, the metal powder having a mean roundness of at least 0.70. The invention also relates to its manufacturing method by argon atomization.

An aluminum alloy based on a total weight of the aluminum alloy, in percentages by weight, includes 9.12% of Si, 8-11% of Zn, 0.5-1.5% of Mg, 0.2-0.8% of Cu, 0-0.6% of Fe, 0.08-0.25% of Mn, 0-0.10% of Sr, 0-0.05% of Sc, 0-0.5% of Er, and 73.2-82.22% of Al.

The present invention discloses a Nb and Al-containing titanium-copper alloy strip, characterized in that the weight percentage composition of the titanium-copper alloy strip comprises: 2.00-4.50 wt % Ti, 0.005-0.4 wt % Nb, and 0.01-0.5 wt % Al, balance being Cu and unavoidable impurities. Preferably, in the microstructure of the titanium-copper alloy strip, the number of Nb and Al-containing intermetallic compound particles with a particle size of 50-500 nm is not less than 1×10.sup.5/mm.sup.2, and the number of Nb and Al-containing intermetallic compound particles with a particle size greater than 1 μm is not more than 1×10.sup.3/mm.sup.2. Under the condition of ensuring excellent bendability, the titanium-copper alloy strip has excellent stability, especially the stability of mechanical properties at high temperatures. The present invention also relates to a method for producing the titanium-copper alloy strip.

The present invention discloses a Nb and Al-containing titanium-copper alloy strip, characterized in that the weight percentage composition of the titanium-copper alloy strip comprises: 2.00-4.50 wt % Ti, 0.005-0.4 wt % Nb, and 0.01-0.5 wt % Al, balance being Cu and unavoidable impurities. Preferably, in the microstructure of the titanium-copper alloy strip, the number of Nb and Al-containing intermetallic compound particles with a particle size of 50-500 nm is not less than 1×10.sup.5/mm.sup.2, and the number of Nb and Al-containing intermetallic compound particles with a particle size greater than 1 μm is not more than 1×10.sup.3/mm.sup.2. Under the condition of ensuring excellent bendability, the titanium-copper alloy strip has excellent stability, especially the stability of mechanical properties at high temperatures. The present invention also relates to a method for producing the titanium-copper alloy strip.

An enhanced aluminum alloy galvanically compatible with a magnesium alloy component is disclosed. The aluminum alloy comprises aluminum, less than 0.2 weight percent copper, less than 0.2 weight percent iron, 6.0 to 9.0 weight percent silicon, 0.6 to 1.5 weight percent magnesium, and greater than 0.8 weight percent manganese. The aluminum alloy further comprises less than 2 weight percent zinc, less than 0.1 weight percent nickel, less than 0.2 weight percent tin, less than 0.05 weight percent titanium; and 0.008 to 0.02 weight percent strontium. Manganese and iron have a weight ratio of at least 30:1. Furthermore, iron and manganese combined content is less than 2.0 weight percent.

A SnBiSb series low-temperature lead-free solder and a preparation method thereof, which belongs to the technical field of low-temperature soldering. The lead-free solder includes by weight the following composition: 32.8-56.5% of Bi, 0.7-2.2% of Sb, with the remainder being Sn, wherein the weight percentages of Bi and Sb satisfy a relationship of b=0.006a2−0.672a+19.61+c, wherein the symbol a represents the weight percentage of Bi, the symbol b represents the weight percentage of Sb, and the range of c is −1.85≤c≤1.85. The solder alloy has a peritectic or near peritectic structure with a low melting point, and has an excellent mechanical performance and reliability, and applicable to the field of low-temperature soldering.

A SnBiSb series low-temperature lead-free solder and a preparation method thereof, which belongs to the technical field of low-temperature soldering. The lead-free solder includes by weight the following composition: 32.8-56.5% of Bi, 0.7-2.2% of Sb, with the remainder being Sn, wherein the weight percentages of Bi and Sb satisfy a relationship of b=0.006a2−0.672a+19.61+c, wherein the symbol a represents the weight percentage of Bi, the symbol b represents the weight percentage of Sb, and the range of c is −1.85≤c≤1.85. The solder alloy has a peritectic or near peritectic structure with a low melting point, and has an excellent mechanical performance and reliability, and applicable to the field of low-temperature soldering.

Provided are a solder alloy and a solder joint, which have a narrow ΔT to suppress solder bridges and solder icicles, and a small amount of dross generated in a solder tank, suppress Cu leaching, and have higher strength. The solder alloy has an alloy composition of, by mass %, Cu: more than 2.0% and less than 3.0%; Ni: 0.010% or more and less than 0.30%; and Ge: 0.0010 to 0.20% with the balance being Sn. Preferably, by mass %, Cu is more than 2.5% and less than 3.0%, and the alloy composition satisfies the following relations (1) and (2): ≤2.400≤Cu+Ni+Ge≤3.190 (1), and 0.33≤Ge/Ni≤1.04 (2). Cu, Ni, and Ge in the relations (1) and (2) each represent the contents (mass %) in the alloy composition.