Answer:
1. High friction
2. High extrusion temperature
Explanation:
Surface cracking on extruded products are defects or breakage on the surface of the extruded parts. Such cracks are inter granular.
Surface cracking defects arises from very high work piece temperature that develops cracks on the surface of the work piece. Surface cracking appears when the extrusion speed is very high, that results in high strain rates and generates heat.
Other factors include very high friction that contributes to surface cracking an d chilling of the surface of high temperature billets.
Answer:
Estimated number of indigenous faults remaining undetected is 6
Explanation:
The maximum likelihood estimate of indigenous faults is given by,
here,
= the number of unseeded faults = 6
= number of seeded faults = 30
= number of seeded faults found = 15
So NF will be calculated as,
And the estimate of faults remaining is 
= 12 - 6 = 6
Explanation:
Anodizing :
Anodizing is the surface protection process from the environment.As we know that due to external environment surfaces get corrodes .By using anodizing process the outer surface of material coated by using different type of coating material.
As the name stand that in the anodizing process there will be anode and oxygen.in this process oxidation of material take place .
Oxides of aluminium and magnesium are stable that is why they anodized by this process.
