The present invention provides a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, wherein the silicon nitride crystal grains are covered with the grain boundary phase and width of the grain boundary phase is 0.2 nm or more. It is preferable that the width of the grain boundary phase is 0.2 nm to 5 nm. Additionally, it is preferable that the silicon nitride sintered body includes 15% by mass or less of the grain boundary phase. According to the above-described configuration, it is possible to provide a high-temperature-resistant silicon nitride sintered body in which degradation of the grain boundary phase under high temperature environment is suppressed. This silicon nitride sintered body is suitable for constituent material of a high-temperature-resistant member, use environment of which is 300 C. or higher.

The present disclosure relates to a lead-free solder alloy composition in which a nanosized ceramic powder additive is added to a lead-free solder alloy of SnCuBi, SnAgBi or SnAgCuBi, and a method for preparing the same.

The present disclosure relates generally to welding and, more specifically, to electrodes for arc welding, such as Gas Metal Arc Welding (GMAW) or Flux Core Arc Welding (FCAW). A welding consumable includes a metallic sheath surrounding a granular core. The welding consumable includes: approximately 0.35 wt % or less manganese, between approximately 0.1 wt % and approximately 3 wt % nickel, between approximately 2.5 wt % and approximately 10 wt % calcined rutile; and between approximately 0.1 wt % and approximately 2 wt % spodumene, all based on the weight of the welding consumable.

A conductive paste including (A) a silver powder, (B) a glass frit, (C) an organic binder and (D) a powder containing Cu and at least one metal element selected from the group consisting of V, Cr, Mn, Fe and Co. The powder (D) may thus contain Cu and Mn, Cu and Fe or Cu and Co. The conductive paste has a desirable electromigration resistance, solder heat resistance and adhesiveness to a substrate.

The present invention relates to a metal paste including: a first metal powder including nickel (Ni); a second metal powder including at least one selected from the group consisting of tin (Sn), zinc (Zn), bismuth (Bi), and indium (In); and a dispersing agent, and to a thermoelectric module which adopts a bonding technique using the metal paste.

A tubular welding electrode for arc welding that has improved crack resistance comprises a steel sheath disposed around a granular powder flux fill core. The granular powder flux fill core comprises magnesium oxide and a sulfur source such as iron sulfide.

The invention described herein pertains generally to a process for making boric acid free flux compositions in which boric acid and/or borax is substituted with a molar equivalent amount of potassium tetraborate tetrahydrate. In some embodiments, a phthalocyanine pigment is used to affect a color change at activation temperature.

Utilizing a hydrogen compound source as an arc stabilizer is counter-intuitive to standard formulation design practices which often strive to limit or eliminate hydrogen from the welding arc and weld pool. The present disclosure is directed to a tubular metal-cored welding electrode that comprises a metallic sheath disposed around a granular metal core in which the granular metal core comprises an alginate arc stabilizer (as a hydrogen compound source) configured to release hydrogen near a surface of a workpiece during welding. The tubular metal-cored welding electrode may further comprise primary de-oxidizers such as manganese and silicon. In certain embodiments, the amount of manganese in the tubular metal-cored welding electrode may be minimized or eliminated. The tubular metal-cored welding electrode may also comprise nickel or titanium.

The invention described herein pertains generally to boric acid free flux composition in which boric acid and/or borax is substituted with a molar equivalent amount of potassium tetraborate tetrahydrate. In some embodiments, a phthalocyanine pigment is used to effect a color change at activation temperature.

The preparation and use of particulate metallic solder alloy having particles of a single chemical composition is described. The particles of the particulate metallic solder alloy have a bimodal size distribution in which particles in a smaller size range have a largest dimension that is smaller than a smallest dimension of particles in a larger size range of the bimodal distribution. In some examples the particles in the smaller size mode have dimensions in the range of 1 to 100 nm. In some examples, the particles in the larger size mode have dimensions in the range of 2 to 75 microns in dimension. In some examples, a halogen-free flux is used. In some examples, a solvent is used to make a paste.