The researchers studied how the way graphite fibers are spread and lined up in copper composites affects their ability to resist cracking from heat expansion. They made test samples with different methods and fiber amounts, then measured how much they expanded when heated and how strong they were. They found that composites with fibers mixed chemically could withstand the highest temperatures before cracking. Also, as more fibers were added, the composites could handle higher temperatures even though they were less strong under pressure.