What is the difference between the normal physics and quantum physics? Are Can we use the quantum physics in metallurgical operations

Classical physics is causal; complete knowledge of the past allows computation of the future. Likewise, complete knowledge of the future allows precise computation of the past. (Chaos theory is irrelevant to this statement; it talks about how well you can do with incomplete knowledge.)

Not so in quantum physics. Objects in quantum physics are neither particles nor waves; they are a strange combination of both. Given complete knowledge of the past, we can make only probabilistic predictions of the future.

In classical physics, two bombs with identical fuses would explode at the same time. In quantum physics, two absolutely identical radioactive atoms can and generally will explode at very different times. Two identical atoms of uranium-238 will, on average, undergo radioactive decay separated by billions of years, despite the fact that they are identical.

There is a rule that physicist often use to separate classical physics from quantum. If Planck’s constant appears in the equations, it is quantum physics. If it doesn’t, it is classical physics.

Most physicists believe that quantum physics is the right theory, even though many details are yet to be worked out. Classical physics can be derived from quantum physics in the limit that the quantum properties are hidden. That fact is called the “correspondence principle.”
Yes quantum physics is used in metallurgy as it explains what holds atom in a metal are the valence electrons due to which properties such as hardness, strength and fracture resistance are studied.