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.

Alloys and processes for making and using same. In some examples, an alloy can include greater than 50 wt % to less than 65 wt % bismuth; greater than 35 wt % to less than 50 wt % tin; about 0.01 wt % to about 2.5 wt % indium; and at least one of: about 0.01 wt % to about 2.5 wt % antimony, about 0.01 wt % to about 0.5 wt % gallium, about 0.01 wt % to about 4 wt % zinc, and about 0.01 wt % to about 2.5 wt % chromium, with all weight percent values based on a total weight of the alloy. In other examples, an alloy can include greater than 50 wt % to less than 65 wt % bismuth; greater than 35 wt % to less than 50 wt % tin; about 0.01 wt % to about 2.5 wt % indium, and less than 1 wt % of lead, with all weight percent values based on a total weight of the alloy.

Alloys and processes for making and using same. In some examples, an alloy can include greater than 50 wt % to less than 65 wt % bismuth; greater than 35 wt % to less than 50 wt % tin; about 0.01 wt % to about 2.5 wt % indium; and at least one of: about 0.01 wt % to about 2.5 wt % antimony, about 0.01 wt % to about 0.5 wt % gallium, about 0.01 wt % to about 4 wt % zinc, and about 0.01 wt % to about 2.5 wt % chromium, with all weight percent values based on a total weight of the alloy. In other examples, an alloy can include greater than 50 wt % to less than 65 wt % bismuth; greater than 35 wt % to less than 50 wt % tin; about 0.01 wt % to about 2.5 wt % indium, and less than 1 wt % of lead, with all weight percent values based on a total weight of the alloy.

The present invention provides a thermally deformable annular packer with pressure relief means for use in oil and gas wells. The annular packer is formed from a stack of component parts, said parts comprising one or more eutectic alloy based ring sections sandwiched between two end sections. At least one of the annular packer component parts has one or more enclosed voids that are configured to become exposed when the packer is subjected to a predetermined pressure or temperature. The exposure of the enclosed voids serves to increase the effective volume within the sealed region formed by the annular packer in the annulus between two coaxial well casing/tubing. The increase in the effective volume serves to reduce the pressure within the sealed region thus preventing a build-up of pressure that might otherwise have damaged the well casing/tubing.

A thermoelectric conversion material has a La.sub.2O.sub.3-type crystal structure and is of n-type. The thermoelectric conversion material has a composition represented by Mg.sub.3+m-a-bA.sub.aB.sub.bD.sub.2-e-fE.sub.eF.sub.f. D is at least one of Sb or Bi. E is at least one of P or As. m is a value of greater than or equal to −0.1 and less than or equal to 0.4. e is a value of greater than or equal to 0.001 and less than or equal to 0.25. A is at least one of Y, Sc, La, or Ce. F is at least one of Se or Te. a and f are values that satisfy a condition of 0.0001≤a+f≤0.06. B is at least one of Mn or Zn. b is a value of greater than or equal to 0 and less than or equal to 0.25.

A solder joint, for bonding an electrode of a circuit board to an electrode of an electronic component, that includes: an Sn—Bi-based solder deposited on the electrode of the circuit board; and a solder alloy deposited on the electrode of the electronic component. The Sn—Bi-based solder alloy has a lower melting point than the solder alloy deposited on the electrode of the electronic component. Fine Bi phases in the solder joint each have an area of less than or equal to 0.5 μm.sup.2. Coarse Bi phases in the solder joint each have an area of greater than 0.5 μm.sup.2 and less than or equal to 5 μm.sup.2. A proportion of the fine Bi phases among the fine Bi phases and the coarse Bi phases is greater than or equal to 60%.

A solder joint, for bonding an electrode of a circuit board to an electrode of an electronic component, that includes: an Sn—Bi-based solder deposited on the electrode of the circuit board; and a solder alloy deposited on the electrode of the electronic component. The Sn—Bi-based solder alloy has a lower melting point than the solder alloy deposited on the electrode of the electronic component. Fine Bi phases in the solder joint each have an area of less than or equal to 0.5 μm.sup.2. Coarse Bi phases in the solder joint each have an area of greater than 0.5 μm.sup.2 and less than or equal to 5 μm.sup.2. A proportion of the fine Bi phases among the fine Bi phases and the coarse Bi phases is greater than or equal to 60%.

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).

Provided is a preform solder including a first metal containing Sn and a second metal formed of an alloy containing Ni and Fe. Alternatively, provided is a preform solder (1) having a metal structure including a first phase (10) that is a continuous phase and a second phase (20) dispersed in the first phase (10), the first phase (10) contains Sn, the second phase (20) is formed of an alloy containing Ni and Fe, and a grain boundary (15) of a metal is present in the first phase (10).