Final answer:
d.Braze joint. joint that involves joining metal parts using metallic mixtures or alloys with a melting point up to 840 degrees Fahrenheit is known as a
Step-by-step explanation:
A joint obtained by the joining of metal parts with metallic mixtures or alloys that melt at a temperature up to and including 840 degrees Fahrenheit is a D. Braze joint. Soldering and brazing are techniques used to join metals without melting the base metal.
Solder joints involve materials that melt below 840°F, whereas brazing involves a filler metal that melts above this temperature but below the melting point of the base metals.
Welding, on the other hand, typically involves the melting of the base metals themselves to form a joint. Fusion joints are typically associated with welding processes where the base material melts and fuses together.
Given the temperature criterion in the question, brazing fits the description.
A joint obtained by the joining of metal parts with metallic mixtures or alloys that melt at a temperature up to and including 840 degrees Fahrenheit is called a Braze joint.
Braze joints are created by using a filler material called brazing alloy which has a lower melting point than the base metals being joined. The brazing alloy is melted and flows into the joint, forming a strong bond as it solidifies.
Unlike welding, which requires the base metals to be melted, brazing is a process used to join metal parts without melting the base metals.